A method for manufacturing a recessed wall lined with bristle for a mouthpiece for simultaneous brushing of multiple dental positions, and a recessed wall and mouthpiece obtained by the method; a dental cleaning device; a mouthpiece for brushing of multiple dental positions, a brushing device including such a mouthpiece, and a method for operating such a mouthpiece or brushing device.

Abstract

To provide a method for manufacturing a recessed wall lined with bristles for a mouthpiece for simultaneously brushing at a plurality of dental positions.SOLUTION: An elongated continuous bristled sheet component having a first side lined with a plurality of bristles is provided. The sheet component defines a length axis extending parallel to the sheet component and defines a cross-sectional shape as viewed transverse to the length axis. In an initial state, the cross-sectional shape of the sheet component has an initial shape, and the length axis has an arch shape. The sheet component is transformed from an initial state to a final state to provide a recess wall. In the final state, the cross-sectional shape has a final U-shape, the length axis is arcuate, and the first side is a concave inner side of the final U-shape. The first side is more concave in the final state than in the initial state.SELECTED DRAWING: Figure 22

Description

【Technical Field】 【0001】 Introduction The present application relates to a plurality of inventions in the field of dental cleaning devices for brushing teeth and / or dental positions. More specifically, the plurality of inventions relate to the field of dental cleaning devices for simultaneously brushing at a plurality of dental positions. 【0002】 The plurality of inventions of the present application are divided into three chapters. 【0003】 The first chapter corresponds to Dutch Patent Application No. 2021332, a priority application filed on July 17, 2018, under the title "Method for manufacturing a recess wall lined with bristles for a mouthpiece for simultaneously brushing at a plurality of dental positions, and a recess wall and a mouthpiece obtained by that method". As can be seen from this title, the first chapter relates in particular to a method for manufacturing a recess wall lined with bristles for a mouthpiece. The present application claims the priority of Dutch Patent Application No. 2021332. 【0004】 The second chapter corresponds to Dutch Patent Application No. 2021330, a priority application filed on July 17, 2018, under the title "Dental cleaning device". The second chapter relates in particular to operating a mouthpiece so that the mouthpiece performs its brushing action. The present application claims the priority of Dutch Patent Application No. 2021330. 【0005】 Chapter 3 corresponds to Netherlands Patent Application No. 2021331, a priority application filed on July 17, 2018, entitled “Mouthpiece for brushing at multiple dental positions, brushing device including such mouthpiece, and method for operating such mouthpiece or brushing device.” Chapter 3 relates, in particular, to specific configurations of the mouthpiece or recessed wall. This application claims priority to Netherlands Patent Application No. 2021331. 【0006】 The dental cleaning devices in Chapter 2 may, but are not necessarily, include recessed walls manufactured by the methods described in Chapter 1. Furthermore, the recessed walls of the cleaning devices in Chapter 2 may be manufactured in other ways. 【0007】 Furthermore, the dental cleaning device of Chapter 2 may, but is not necessarily, have a mouthpiece or recessed wall configured according to one of the embodiments of Chapter 3. Also, the mouthpiece or recessed wall of Chapter 2 may be configured differently. 【0008】 The mouthpiece in Chapter 3 may, but is not necessarily, include a recessed wall manufactured by the method described in Chapter 1. Furthermore, the recessed wall of the mouthpiece in Chapter 3 may be manufactured in other ways. 【0009】 Furthermore, the mouthpiece in Chapter 3 may operate according to Chapter 2, but this is not necessarily the case. Also, the mouthpiece in Chapter 3 may operate in different ways. 【0010】 The description of this application is arranged according to these three chapters, as also shown in this description. Each claim includes a header indicating which chapter it belongs to. 【0011】 Each chapter uses similar features corresponding to the technical terms. In the event of any discrepancy between technical terms used in one chapter and those used in another, the technical terms used in one chapter shall take precedence over those in the other chapter within that chapter. 【0012】 Chapter 1 [Title of Invention] Method for manufacturing a recessed wall lined with bristle for a mouthpiece for simultaneous brushing of multiple dental positions, and recessed wall and mouthpiece obtained by the method 【0013】 Chapter 1 of the present invention relates to the field of dental cleaning devices having a mouthpiece for brushing multiple dental positions simultaneously, and more particularly to a dental cleaning device of the type in which the mouthpiece includes a body portion provided with at least one recess, the at least one recess being defined by a recess wall lined with a plurality of bristles, the plurality of bristles extending from the recess wall into the recess, the recess wall defining an arch-shaped longitudinal axis, defining a U-shaped cross-sectional shape when viewed transversely to the longitudinal axis, and is configured to encompass a plurality of dental positions along the dental arch. [Background technology] 【0014】 [Background Technology for Chapter 1] Cleaning the teeth of humans and animals is essential for oral hygiene and internal health. Various dental cleaning devices are available, such as manual and electric toothbrushes. With these typical toothbrushes, it is recommended to brush your teeth in the prescribed manner for at least two minutes a day to effectively remove plaque. However, the average person does not spend the entire prescribed time cleaning their teeth, nor do they always brush according to the effective method. Additionally, brushing teeth with a toothbrush can be difficult for people with disabilities, the elderly, or children. This is because typical toothbrushes require precise positioning of the brush bristles on the various surfaces of the teeth. 【0015】 As is common in older adults, when teeth are missing in some or all dental locations, cleaning the gums in these locations remains an essential condition for oral hygiene and internal health. 【0016】 To clean the teeth and / or gums in these dental locations, there is a need for automatic brushing of the teeth and / or gums in those dental locations, thereby reducing the time and effort required for effective brushing. In addition, there is a need to avoid the need to carefully manipulate the brush. 【0017】 Dental cleaning devices are known that include a mouthpiece covering the maxillary and / or mandibular dental arches. These mouthpieces may be of a type that includes a body provided with at least one recess, the at least one recess being bounded by a recess wall lined with a plurality of bristles, the plurality of bristles extending from the recess wall into the recess, the recess wall defining an arch-shaped longitudinal axis, defining a U-shaped cross-sectional shape when viewed transversely to the longitudinal axis, and is configured to encompass a plurality of dental positions along the dental arch. Dental positions to be brushed, such as teeth and / or gums, are inserted into at least one recess, and the recess wall lined with bristles is operated by the bristles on the recess wall to brush the teeth and / or gums. Depending on the length of the recess, some or all dental positions of the maxillary and / or mandibular dental arches can be brushed simultaneously. An example of such a mouthpiece can be found in Patent Document 1, filed by the applicant on April 27, 2018. This PCT application has not yet been published as of the priority date of this application. 【0018】 A portion of such a mouthpiece is a recessed wall lined with bristle, which is arched in the longitudinal direction and has a U-shaped cross-section transversely to this longitudinal direction, with the bristle on the inner side of the U-shape. The small inner space of the U-shaped cross-section and the length of the arch make the manufacture of such a recessed wall lined with bristle extremely difficult. Naturally, such a recessed wall lined with bristle can be manufactured manually by attaching the bristle or bristle tufts one by one to the recessed wall. However, this is labor-intensive and not time-efficient or cost-efficient. Such a recessed wall with a U-shaped cross-section and bristle on the inner side of the U-shape can further be manufactured by injection molding the recessed wall and bristle simultaneously, but due to the small inner width of the U-shape, demolding the molded recessed wall and bristle from the mold is almost impossible without damaging the bristle. Furthermore, tufting the inner walls of narrow, arched channels with a U-shaped cross-section cannot be automated. 【0019】 Therefore, there is a need for a method for manufacturing a continuous recessed wall lined with bristle for simultaneous brushing at multiple dental positions arranged along an arch that extends at least equal to the distance from the left second premolar to the right second premolar. There, the recessed wall is configured to encompass dental positions associated with at least the left second premolar to at least the right second premolar, and has a U-shaped cross section and an arch-shaped length axis that extends at least equal to the distance from the left second premolar to the right second premolar. [Prior art documents] [Patent Documents] 【0020】 [Patent Document 1] International Application No. PCT / NL2018 / 050276 [Patent Document 2] German Patent Application Publication No. 103.03.548 Specification [Summary of the Invention] [Problems to be Solved by the Invention] 【0021】 [Summary of the Invention in Chapter 1] The object of the invention in Chapter 1 is an alternative method for manufacturing a recess wall for a mouthpiece for simultaneous brushing at a plurality of dental positions, the recess wall defining a narrow arch-shaped channel having a U-shaped cross-section, having a length at least equal to the distance from the left second premolar to the right second premolar, and being covered by bristles on the inner sides of the channel, to provide a method. [Means for Solving the Problems] 【0022】 According to a first aspect of the invention in Chapter 1, one or more of the above objects are achieved by providing the method according to claim 1. 【0023】 According to the invention in Chapter 1, a method for manufacturing a continuous recess wall lined with bristles for a mouthpiece for simultaneous brushing at a plurality of dental positions is provided. In other words, the method results in a recess wall configured to brush simultaneously at a plurality of dental positions. If a natural or artificial tooth element is present at the dental position where the bristles on the recess wall brush, this tooth element is brushed. If a tooth element is not present at the dental position where the bristles on the recess wall brush, the gum may be brushed. 【0024】 The continuous recess wall obtained by the method according to the invention of Chapter 1 has an arch-shaped longitudinal axis and, when viewed in a direction transverse to the longitudinal axis, has a U-shaped cross-section configured to encompass the plurality of dental positions. The arch-shaped longitudinal axis has a length extending at least equal to the distance from the left second premolar to the right second premolar. Furthermore, the arch-shaped longitudinal axis can have a shape similar to the shape of the human dental arch. 【0025】 The method according to the invention of Chapter 1 includes a step of providing. In this step of providing, an elongated continuous bristled sheet part having a first side lined with a plurality of bristles is provided. This elongated continuous bristled sheet part can be provided as a prefabricated prefab part made elsewhere, or in the step of providing, the elongated continuous bristled sheet part having an arch-shaped longitudinal axis and a first side lined with bristles can be produced, for example, by assembling the sheet part and the bristles into an integral part, by injection molding the sheet part and the bristles, by injection molding the sheet part into a mold (wherein bristles (e.g., of nylon) are installed as inserts and become an integral part with the molded sheet part), or can be created in any other suitable manner for obtaining a sheet part having a first side lined with bristles. The elongated continuous bristled sheet part obtained in the step of providing has an initial state, which has an arch-shaped longitudinal axis extending parallel to the bristled sheet part and, when viewed in a direction transverse to the longitudinal axis, has an initial shape as a cross-sectional shape. 【0026】 The method according to the present invention in Chapter 1 further includes a transformation step, in which the bristle-lined sheet component obtained in the providing step is transformed from an initial state to a final state, resulting in the manufacture of a recessed wall. In the final state, the cross-sectional shape has a final U-shape (which can correspond to the U-shaped cross-section of the recessed wall to be manufactured), the length axis is arched, and the first side is the concave inner side of the final U-shape. A further characteristic of the final state is that in the final state, the first side (of the bristle-lined sheet component) lined with bristle is more concave than in the initial state. 【0027】 This method allows the bristle-equipped seat component, which will be provided in the step provided, to be prefabricated elsewhere, or allows the bristle-equipped seat component to be fabricated in-situ, such that the first side of the seat component (i.e., the side that will be lined by the bristle) is, for example, flat, convex, or shallow concave, and that it is easily accessible for fabricating the bristle-equipped seat component. In the initial state, the bristle can extend from the seat component in essentially the same direction, and the bristle can extend, for example, substantially parallel to one another. The bristle can also be grouped into one or more groups of parallel bristle, with different groups of bristle extending in different directions relative to one another. For example, the flat or convex first sides of the sheet component in its initial state allow for easy removal of the molded half when demolding the molded sheet component and / or bristle (see, for example, Patent Document 2) when the sheet component and / or bristle are injection molded, as described in Patent Document 2, in which a sheet component with bristle for a conventional toothbrush is manufactured by injection molding the sheet component in several steps and by inserting the bristle tuft into the molded half. Furthermore, the flat or convex first sides of the sheet component in its initial state also allow for the use of other techniques to assemble the sheet component with bristle, such as the AFT toothbrush technology offered by GB Boucherie NV, Belgium, or the technology of Zahoransky AG, Germany, such as the anchorless toothbrush. This pre-assembled sheet component with bristle is then subjected to a transformation step, in which the initial state of the sheet component with bristle is transformed into a recessed wall to be manufactured, which has a final state.In this transformation step, the bristle-equipped sheet component obtained in the providing step is brought to its final U-shaped cross section, in which the bristle on the opposing sides of the U-shaped cross section extends toward each other and can intersect with each other. 【0028】 According to further embodiments of the present invention in Chapter 1, the final U-shape may be defined by two legs and a base connecting these legs, and the vertical axis may be defined to extend transversely with respect to the base between the legs. According to this embodiment, in the final state, bristles on one leg and bristles on the other leg may extend toward each other from their respective legs. Furthermore, according to this embodiment, in addition or alternatively, and in view of the final state, bristles on the legs may be provided at a predetermined angle with respect to the vertical axis, the angle being in the range of 30° to 90° with respect to the vertical axis. 【0029】 According to further embodiments of the present invention in Chapter 1, two legs and a base connecting these legs are defined by a final U-shape, the vertical axis is defined as extending transversely with respect to the base, the legs define tangents to the first side of the bristle-equipped seat component at the respective roots of the bristle on the legs, the tangents extending in a plane transverse with respect to the length axis; in the initial state, the bristle can extend parallel to the vertical axis, and each of the tangents can have its respective predetermined initial angle with respect to the vertical axis; in the transformation step, the legs are bent toward each other, rotating each tangent by an angle of x° with respect to the vertical axis, so that the bristle associated with each tangent extends at an angle of x° with respect to the vertical axis in a direction away from the base. If the legs are straight and do not bend when the legs are bent toward each other, this further embodiment may also be represented as an embodiment in which two legs and a base connecting these legs are defined by a final U-shape, and the vertical axis is defined as extending transversely with respect to the base; the bristle may, in the initial state, extend parallel to the vertical axis; at least a portion of the bristle on the legs may, in the final state, extend at an angle of x degrees with respect to the vertical axis in a direction away from the base; the legs may, in the initial state, have an initial angle with respect to the vertical axis; and the legs may, in the final state, have a final angle with respect to the vertical axis, the final angle being x degrees greater than the initial angle. 【0030】 By doing so, i) the prefabricated part (i.e., the bristle-equipped seat part) is provided in the providing step, all bristles are parallel to each other and to the perpendicular axis, which greatly simplifies the fabrication of the prefabricated part. Next, in the transforming step, the legs are rotated toward each other over an angle of x degrees with respect to the vertical, so that in the final state, the bristle on the legs extends over an angle of x degrees with respect to the vertical. The value of x can be in the range of 0° to 90° according to the invention in Chapter 1, for example, in the range of 30° to 60°, for example, in the range of 40° to 50°. Additionally or alternatively, the final angle of the leg with respect to the vertical axis can be in the range of 0° to 45° according to the present invention in Chapter 1, for example, in the range of 5° to 20°. 【0031】 According to further embodiments of the present invention in Chapter 1, an elongated continuous bristle sheet part having an arched longitudinal axis and a first side lined with bristle is manufactured in the providing step. The providing step can then be initiated with a (elongated, continuous) sheet part (still without bristle) as a pre-fabricated part. This sheet part may be manufactured, for example, from TPE or from any other suitable sheet part material, whether or not described in this Chapter 1. Then, during the providing step, it (still not a bristle sheet part) is provided with bristle or bristle tuft. Each of these bristle and tuft bristle may be made from nylon or PBT (polybutylene terephthalate), or from any other suitable bristle material, whether or not described in this Chapter 1. The bristle or bristle tuft will be fixed to a sheet component. This fixing of the bristle to the sheet component can be by tufting, bonding, fusing, or any other method, whether or not described in this Chapter 1. The sheet component with the bristle thus obtained will then be subjected to the modification steps of the method according to the present invention in Chapter 1. 【0032】 According to further embodiments of the present invention in Chapter 1, the bristle has a root end, a free end, and a bristle body portion extending from the root end to the free end, and the bristle-equipped seat component obtained in the providing step is produced by tufting (in or before the providing step), and the tufting is - The steps include inserting multiple nylon bristle or nylon bristle tufts through a first sheet component, such that the bristle body and free end extend from the front side of the first sheet component, and the root end protrudes from the back side of the first sheet component; - Optionally, the step of providing a second seat component by contacting the back side of a first seat component; - The step of fusing the root end of the bristle with the first seat component and / or (if present) the second seat component, Includes. 【0033】 Tufting may be performed during the serving step, but the tufted bristle-equipped sheet component may also be a pre-fabricated component delivered to the serving step. In the latter case, tufting would have already been performed prior to the serving step, for example, at a much earlier time and / or at a different location than where the serving step is performed. Providing an optional second sheet component may be done by injection molding the second sheet component against the back of the first sheet component. Alternatively, the second sheet component may be a pre-fabricated component, which is positioned against the back of the first sheet component and heated to fuse its roots to the second sheet component. When the second sheet component is not present, the root ends will be fixed to the first sheet, for example, by fusing them to the first sheet. If an optional second sheet exists, the root portion is fixed to the first and / or second sheet component, for example, by fusing the root portion to one or both of the sheet components. Thus, tufting can be carried out according to already known methods, for example, the method described in Patent Document 2. 【0034】 According to further embodiments of the present invention in Chapter 1, the bristle-equipped sheet component can be transformed from an initial state to a final state by thermoforming in the transformation step. Thermoforming can be performed, for example, by vacuum forming. The bristle-equipped sheet component can be placed in a mold with a second side facing into a U-shaped mold cavity and a first side with bristle facing away from the U-shaped mold cavity, and thereafter the mold cavity can be vacuumed, drawing the bristle-equipped sheet component into the cavity and taking the shape of a U-shaped cavity. When transforming the bristle-equipped sheet component from an initial state to a final state, the bristle-equipped sheet component can be stretched by thermoforming according to the present invention in Chapter 1. According to further embodiments, in the final state and when viewed in the direction along the U-shaped contour, the bristle can be regularly distributed. Furthermore, or alternatively, in the initial state, the distribution of bristle on a bristle-equipped sheet part may be configured such that, in the final state, and when viewed along the U-shaped contour, the bristle is distributed regularly or according to a predetermined pattern. In other words, the bristle pattern in the initial state is determined such that, taking into account that the stretching of the sheet part occurs during thermoforming, a predetermined pattern (e.g., regular distribution) is obtained in the final state. 【0035】 According to further embodiments of the present invention in Chapter 1, the length axis can have the same curvature in the initial state as it does in the final state, that is, the curvature of the length axis is not changed in the transformation step. 【0036】 According to further embodiments of the invention in Chapter 1, the longitudinal axis of a bristle-type seat component can have an initial curvature in the initial state and a final curvature in the final state, with the initial curvature being wider than the final curvature. In the transformation step, the curvature of the longitudinal axis of the bristle-type seat component is reduced from a wide initial curvature to a narrow final curvature. Reducing the curvature of the longitudinal axis supports or facilitates a transformation of the cross-sectional shape to a more concave shape than it had in the initial state. In this regard, it may be more useful when the cross-sectional shape of the bristle-type seat component already has a concave shape (it is not more concave than in the final configuration) with respect to the first side of the bristle-type seat component. 【0037】 According to further embodiments of the present invention in Chapter 1, the bristle-equipped seat component has two boundary edges, the two boundary edges (which define the boundary of the bristle-equipped seat component) extending along the length axis at a predetermined mutual distance from each other when viewed in a direction transverse to the length axis (optionally parallel to the length axis), and in the transformation step, the bristle-equipped seat component can be transformed by reducing the mutual distance between the two boundary edges. Using a frame member, the arch curvature of the frame member can be, in its initial state, wider than the final curvature of the bristle-equipped seat component, or it can correspond to the final curvature of the bristle-equipped seat component. 【0038】 According to further embodiments of the present invention in Chapter 1, - The bristle-equipped seat component obtained in the provided step may be bounded by an inner boundary edge and an outer boundary edge, the inner boundary edge and the outer boundary edge extending along the length axis at a predetermined distance from the length axis, - The bristle-equipped seat component can be an integral part with the lingual frame member and the facial frame member, and both the lingual frame member and the facial frame member are curved along their respective arched curves, - The bristle-equipped seat component includes an internal mounting member at the internal boundary edge, the internal mounting member extending along the internal boundary edge (for example, along the entire internal boundary edge) and attached to the lingual frame member; the bristle-equipped seat component includes an external mounting member at the external boundary edge, the external mounting member extending along the external boundary edge (for example, along the entire external boundary edge) and attached to the facial frame member. 【0039】 According to this further embodiment, the facial frame member and the tongue frame member may be provided as one or two separate parts from the bristle-equipped seat component, which are assembled together in the providing step after being provided in the providing step. Next, the steps provided are several sub-steps: - A substep of providing a facial-side frame member and a lingual-side frame member, - A substep of providing a bristle-equipped seat component that is integrated with an inner mounting member and an outer mounting member, separately from the facial-side frame member and the lingual-side frame member, - A substep of attaching the inner mounting member and the outer mounting member to the lingual frame member and the facial frame member, respectively, It is possible to include this. 【0040】 Alternatively, according to this further embodiment, the bristle-equipped seat component, the face-side frame member, and the tongue-side frame member may also be provided as a pre-fabricated integral part, which can be manufactured at very different locations or at very different moments. In other words, the pre-fabricated integral part, including the bristle-equipped seat component, the face-side frame member, and the tongue-side frame member, can be, so to speak, the input to the providing step and the output to the providing step (= the resulting bristle-equipped seat component). The tongue-side frame member and the face-side frame member can be one integral frame member or two separate frame member components. 【0041】 According to further embodiments of the present invention in Chapter 1, the bristle-equipped sheet component, face-side frame member, and tongue-side frame member are manufactured by injection molding (e.g., multi-material injection molding) during or before the steps provided. According to the first example, a bristle tuft (e.g., nylon bristle) may be placed in an injection molding mold, and thereafter, material for forming the sheet component may be injected to overmolde the base of the tuft. According to the second example, a bristle-equipped sheet component (e.g., pre-fabricated according to the first example) may be placed in an injection molding mold, and material for the tongue-side frame member and face-side frame member may be injected into the mold to overmolde together with a portion of the sheet component (e.g., a mounting member). According to the third example, a frame member (for example, pre-fabricated by injection molding) is placed in an injection molding mold, and the bristle and sheet material may be injected to overmolde together with the frame member, or the sheet material may be injected to overmolde together with both the tuft insert (as in the first example) and the frame member. According to the fourth example (which may be combined with the first example), frame material for the face-side frame member and the tongue-side frame member, as well as sheet material for the sheet part and (if not provided according to the first example) optionally for the bristle, is injected into the mold, and the sheet part and optionally for the bristle, as well as the tongue-side frame member and the face-side frame member, can be formed by injecting the frame material and sheet material simultaneously or sequentially. 【0042】 According to further embodiments of the present invention in Chapter 1, the inner and outer mounting members may be configured as side flaps extending along the inner and outer boundary edges, respectively, and may be configured to be attached (e.g., bonded) to the lingual frame member and the facial frame member, respectively. Bonding may be done by adhesive (or glue), tape, heat welding, or by multi-material injection molding techniques, the multi-material injection molding technique resulting in a fused interface layer where the material for the injected frame member and the material for the injected sheet part come together. 【0043】 According to further embodiments of the present invention in Chapter 1, the inner and outer mounting members may be configured as double-sided flaps extending along the inner and outer boundary edges, respectively, and the tongue-side frame member and face-side frame member are configured with plate components, and the double-sided flap includes a first flap component and a second flap component, the second flap component being parallel to the first flap component and at a predetermined distance from the first flap component, defining a gap between the first and second flap components, the gap being configured to receive the plate components of the tongue-side frame member and face-side frame member, respectively. The plate component inserted into the gap between the flaps will be attached to the flaps, for example, by bonding. Bonding can be done by adhesive (or glue), tape, heat welding, or by a multi-material injection molding technique, the multi-material injection molding technique causing a fused interface layer where the material for the injected frame member and the material for the injected sheet component come together. 【0044】 According to further embodiments of the present invention in Chapter 1, in the steps provided, two of the bristle-equipped seat components are obtained, - Each bristle-equipped seat component is bounded by the inner boundary edge and the outer boundary edge, the inner boundary edge and the outer boundary edge extending along the length axis at a predetermined distance from the length axis, - Each bristle-equipped seat component is an integral part with the tongue-side frame member and the face-side frame member, and both the tongue-side frame member and the face-side frame member are curved in an arc shape along their respective arched curves. - Each bristle-equipped seat component includes the inner mounting member on the inner boundary edge, the inner mounting member extending along the inner boundary edge and attached to the lingual frame member, and each bristle-equipped seat component includes the outer mounting member on the outer boundary edge, the outer mounting member extending along the outer boundary edge and attached to the facial frame member, The face-side frame member associated with the first bristle-equipped seat component of the two bristle-equipped seat components is provided with a male or female part of the first snap connection, and the face-side frame member associated with the second bristle-equipped seat component of the two bristle-equipped seat components is provided with a mating female or male part of the first snap connection, respectively. A tongue-side frame member associated with the first bristle-equipped seat component of the two bristle-equipped seat components is provided with a male or female part of a second snap connector, and a face-side frame member associated with the second bristle-equipped seat component of the two bristle-equipped seat components is provided with a mating female or male part of the second snap connector, respectively. Both female parts of the two snap connectors may be provided on one of the tongue-side frame members and face-side frame members of the set, and on the other hand, the mating male parts of the two snap connectors may be provided on the tongue-side frame member and face-side frame member of the other set. Alternatively, the tongue-side frame member of one set may be provided with a female component for a first snap connection, and the face-side frame member of one set may be provided with a male component for a second snap connection; on the other hand, the tongue-side frame member of the other set may be provided with a male component for a first snap connection, and the face-side frame member of the other set may be provided with a female component for a second snap connection. 【0045】 According to further embodiments of the present invention in Chapter 1, the arch curvature of the lingual and facial frame members obtained by the bristle-equipped sheet component in the providing step can be wider than the final curvature; in the transforming step, the arch curvature is reduced to correspond to a narrower final curvature. Reducing the arch curvature of the frame members after attaching the inner and outer edges of the bristle-equipped sheet component to the respective frame members is a simple action and is easily automated. Reducing these arch curvatures results in simultaneously reducing the curvature of the length axis of the bristle-equipped sheet component, which results in an increase in the concaveness of the first side of the bristle-equipped sheet component. 【0046】 According to further embodiments of the present invention in Chapter 1, the tongue-side frame member and the face-side frame member can be elastic and can have a released state in which the frame member is stress-free and has an arc-shaped curve corresponding to the final curvature of the recessed wall; the method can further include a pre-biasing step, which is performed before or during the providing step; in the pre-biasing step, the frame member is pre-tensioned from a released state to a pre-tensioned state in which the arc-shaped curve of the frame member is widened to correspond to the initial curvature of the bristle-equipped sheet component, and in the pre-tensioned state, the frame member has a pre-tension acting in the direction of returning the frame member to their released state; in the transforming step, the arc-shaped curve is reduced (narrowed) by releasing the pre-tension of the frame member; by doing so, the pre-tension accumulated in the frame member is used to increase the concave surface of the first side of the bristle-equipped sheet component. 【0047】 According to further embodiments of the present invention in Chapter 1, two bristle-equipped seat components may be obtained, and the mounting members of the first and second seat components may be attached to each other, for example, by heat welding. The mounting members may be attached to each other directly, for example, by heat welding, or indirectly via intermediate components, in which case heat welding may be used as well. 【0048】 According to further embodiments of the present invention in Chapter 1, the mouthpiece to be manufactured is of the type having two recesses, each of the two recesses being defined by recess walls lined with the plurality of bristle, the arc-shaped length axes of the recess walls being parallel to each other, and the U-shaped cross-sectional shape opening in opposite directions; the step of providing is to provide the first bristle seat component and the second bristle seat component as a single component having a transition area that integrally connects the first bristle seat component with the second bristle seat component, the transition zone being configured to allow the two bristle seat components to fold relative to each other from a first position to a second position, in the first position the two bristle seat components are aligned, and in the second position the two bristle seat components are folded relative to each other; the method further includes a folding step, in which the bristle seat components are folded relative to each other from a first position to a second position. This folding step can be performed before the transformation step, after the transformation step, or during the transformation step. 【0049】 In a further embodiment, the length of the length axis extends to a distance at least equal to the distance from the left first molar to the right first molar, and for example, to a length at least equal to the distance from the left second molar to the right second molar. 【0050】 According to further embodiments, the bristle-equipped sheet component obtained in the provided steps may be lined with at least 5 bristles per cm², for example, at least 10 bristles per cm². For example, in the case of elastomer bristles injection-molded together with the bristle-equipped sheet component, the bristle-equipped sheet component may be lined with 40 to 200 bristles per cm². For example, in the case of nylon bristles, the bristle-equipped sheet component may be lined with 1,000 to 6,000 bristles per cm². 【0051】 According to further embodiments of the present invention in Chapter 1, the final U-shape may have an internal width in the range of 0 mm to 10 mm, for example, in the range of 2 mm to 12 mm; and / or the final U-shape may have an internal height in the range of 3 mm to 20 mm, for example, in the range of 5 mm to 10 mm. 【0052】 According to further embodiments of the present invention in Chapter 1, the sheet component with bristle has a thickness of up to 15 mm, and has a thickness in the range of, for example, 0.5 mm to 3 mm, where this thickness is defined as the thickness of the sheet component itself, i.e., the thickness without the length of the bristle. 【0053】 According to a second aspect of the present invention in Chapter 1, the present invention relates to a method for manufacturing a mouthpiece of the type comprising a body portion provided with at least one recess, wherein the at least one recess is defined by a recess wall lined with a plurality of bristles, the plurality of bristles extending from the recess wall into the recess, the recess wall defining an arch-shaped longitudinal axis, defining a U-shaped cross-sectional shape when viewed transversely to the longitudinal axis, and is configured to encompass a plurality of dental positions along the dental arch; the recess wall is manufactured by the method according to the first aspect of the present invention in Chapter 1. The bristle-equipped seat component obtained in the provided step may be provided as a separate component from the main body. Furthermore, the bristle-equipped seat component obtained in the provided step can be attached to the main body, for example, before, during, or after the transformation step, to become an integral part of the main body. 【0054】 According to further embodiments of the present invention in Chapter 1, the main body may further include at least one pressure chamber configured to contain a fluid under pressure, and the main body is configured to deform a recessed wall by reciprocating the pressure in at least one pressure chamber. The main body is configured to deform a recessed wall by reciprocating (alternating) the pressure in at least one pressure chamber, causing a sustained, repeated reciprocating motion of the recessed wall and the bristle on the recessed wall. The mouthpiece may include one, two, three, four, five, six, or any other number of pressure chambers that can be filled with fluid, as described in Patent Document 1, which is under the name of the same applicant and has not yet been published as of the priority date of this application. By alternately (reciprocating) increasing the pressure in at least one of the pressure chambers from a reduced pressure state to an increased pressure state, and decreasing the pressure in this pressure chamber from an increased pressure state to a reduced pressure state, and by continuously repeating this reciprocating motion, the recessed wall bearing an optional bristle is moved, resulting in the recessed wall and the bristle acting on an object (teeth and / or gums present in these dental locations) at the dental location to clean the object. 【0055】 According to a third aspect of the present invention in Chapter 1, the present invention relates to a mouthpiece obtained by the method according to a second aspect of the present invention in Chapter 1. 【0056】 According to a fourth aspect of the present invention in Chapter 1, the present invention relates to a recessed wall for a mouthpiece for brushing multiple dental positions simultaneously, the recessed wall being obtained by the method according to the first aspect of the present invention in Chapter 1. 【0057】 According to a fifth aspect of the present invention in Chapter 1, the present invention relates to a mouthpiece of the type for brushing multiple dental positions simultaneously, comprising a body provided with at least one recess, the at least one recess being defined by a recess wall lined with multiple bristles, the multiple bristles extending from the recess wall into the recess, the recess wall defining an arch-shaped longitudinal axis, defining a U-shaped cross-sectional shape when viewed transversely to the longitudinal axis, and configured to encompass multiple dental positions along the dental arch; the recess wall is manufactured by a method according to a first aspect of the present invention in Chapter 1. 【0058】 According to the present invention in Chapter 1, sheet components (sheet components with or without bristle) can be made from plastic (for example, injection-molded or extruded plastic). The plastic can be, for example, a thermoplastic elastomer. 【0059】 [Brief explanation of the drawings in Chapter 1] The present invention as described in Chapter 1 will be further explained with reference to Figures 1 to 20. [Brief explanation of the drawing] 【0060】 [Figure 1] This diagram shows the lower dental arch with its dental position and a system of three orthogonal axes that define the dental arch. [Figure 2a] This is a perspective view of an example of a mouthpiece having a recessed wall fabricated by the method according to the present invention as described in Chapter 1. [Figure 2b]This is an example of a mouthpiece with a recessed wall fabricated by the method according to the present invention in Chapter 1, and is a cross-sectional view indicated by arrow IIb in Figure 2a. [Figure 3a] Chapter 1 schematically illustrates the first method according to the present invention, and shows a bristle-lined sheet component with one side lined by a bristle. [Figure 3b] Chapter 1 schematically illustrates the first method according to the present invention, and shows a mold for plastically deforming a bristle-type sheet component. [Figure 3c] Chapter 1 schematically illustrates the first method according to the present invention, and shows a sheet part with bristle lying on a mold before plastic deformation. [Figure 3d] Chapter 1 schematically illustrates the first method according to the present invention, and shows a bristle-equipped sheet part after plastic deformation. [Figure 3e] Chapter 1 outlines the first method according to the present invention, and Figure 3d shows an enlarged detail IIIe. [Figure 4] This figure schematically shows an example of a recessed wall formed by the method according to the present invention as described in Chapter 1. [Figure 5] This figure schematically illustrates a further step of the method according to the present invention in Chapter 1, which provides two frame members. [Figure 6] Figure 5 schematically shows the recessed wall of Figure 5 mounted within the frame member of Figure 5, illustrating another mode of performing the modified step of the method according to the present invention in Chapter 1. [Figure 7a] Similar to Figure 6, this figure schematically shows the recessed wall of Figure 5 mounted within the frame member of Figure 5, illustrating yet another mode of performing the modification step of the method according to the present invention in Chapter 1, and showing the initial state. [Figure 7b] Similar to Figure 6, this figure schematically shows the recessed wall of Figure 5 mounted within the frame member of Figure 5, illustrating yet another mode of performing the modification step of the method according to the present invention in Chapter 1, and showing the final state. [Figure 8a] Figure 6 shows a schematic combination of transformation methods and Figure 7 shows a combination that is performed simultaneously, and the initial state is shown. [Figure 8b] Figure 6 shows a schematic combination of transformation methods and Figure 7 shows a combination that is performed simultaneously, and the final state is shown in the diagram. [Figure 9a] This diagram schematically shows two bristle-equipped sheet components as a single component in the first state (Figure 8a). [Figure 9b] This diagram schematically shows two bristle-equipped sheet components as a single component in the second state (Figure 8b). [Figure 10a] This diagram schematically shows the relationship between the angle of the U-shaped side component relative to the vertical and the angle of the bristle relative to the vertical, representing the initial state. [Figure 10b] This figure schematically shows the relationship between the angle of the U-shaped side component relative to the vertical and the angle of the bristle relative to the vertical, representing the final state. [Figure 11a] This diagram schematically illustrates the effects of two modes of mechanical transformation of a bristle-equipped seat component from its initial state to its final state, and shows the bristle-equipped seat component in its initial state in a perspective view. [Figure 11b] This diagram schematically illustrates the effects of two modes of mechanically transforming a bristle-equipped seat component from its initial state to its final state, and shows the same bristle-equipped seat component in its final state in a perspective view. [Figure 11c] This diagram schematically illustrates two modes of effects for mechanically transforming a bristle-equipped seat component from its initial state to its final state, and shows cross-sectional views of the first location in the initial and final states. [Figure 11d] This diagram schematically illustrates two modes of effects for mechanically transforming a bristle-equipped seat component from its initial state to its final state, and shows cross-sectional views of the second location in the initial and final states. [Figure 11e] This diagram schematically illustrates the effects of two modes of mechanically transforming a bristle-equipped seat component from its initial state to its final state, and shows cross-sectional views of a third location in the initial and final states. [Figure 12a] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which depicts the initial state. [Figure 12b] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which is a diagram of the final state. [Figure 12c] Chapter 1 shows a further example of an embodiment according to the present invention in a cross-sectional view, which shows two bristle-equipped seat components that will be assembled together. [Figure 12d] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which shows the two bristle-equipped seat components of Figure 12c in an assembled state. [Figure 13a] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which depicts the initial state. [Figure 13b] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which is a diagram showing another initial state. [Figure 13c] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which is a diagram of the final state. [Figure 14a] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which depicts the initial state. [Figure 14b] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which is a diagram of the final state. [Figure 15a] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which is a diagram of the final state. [Figure 15b] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, illustrating how the frame member is attached to the bristle seat. [Figure 15c]Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which shows that the frame member is attached to the bristle seat. [Figure 16a] A further example of the embodiment of the present invention in Chapter 1 in its final state is shown in a cross-sectional view, which shows a single sheet component assembly. [Figure 16b] A cross-sectional view shows a further example of the embodiment of the present invention in Chapter 1 in its final state, illustrating how two such single-sheet component assemblies can be mounted to one another. [Figure 17a] A further example of the embodiment of the present invention in Chapter 1 in its final state is shown in a cross-sectional view, which shows two single sheet component assemblies. [Figure 17b] A cross-sectional view shows a further example of the embodiment of the present invention in Chapter 1 in its final state, illustrating how these two single-sheet component assemblies can be mounted to one another. [Figure 18a] A further example of the embodiment of the present invention in Chapter 1 in its final state is shown in a cross-sectional view, which shows two single sheet component assemblies. [Figure 18b] A cross-sectional view shows a further example of the embodiment of the present invention in Chapter 1 in its final state, illustrating how these two single-sheet component assemblies can be mounted to one another. [Figure 19a] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which depicts the initial state. [Figure 19b] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which is a diagram of the final state. [Figure 20a] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which depicts the initial state. [Figure 20b] Chapter 1 shows a further example of an embodiment of the present invention in a cross-sectional view, which is a diagram of the final state. [Figure 21]This is a schematic diagram showing a portion of the human dental arch. [Figure 22] This figure schematically shows an embodiment of the mouthpiece of the dental cleaning device according to the present invention, as described in Chapter 2. [Figure 23a] This figure schematically shows a cross-section of the mouthpiece in the reduced pressure state shown in Figure 22. [Figure 23b] This figure schematically shows a cross-section of the mouthpiece in Figure 22 under the increased pressure conditions. [Figure 24] This figure schematically illustrates an embodiment of the dental cleaning device according to the present invention, as described in Chapter 2. [Figure 25] This diagram schematically shows a graph of the pressure inside a pressure chamber as a function of time. [Figure 26] This figure schematically illustrates tooth rubbing by the bristle of a dental cleaning device according to an embodiment of the present invention described in Chapter 2. [Figure 27] This diagram shows the lower dental arch with its dental position and a system of three orthogonal axes that define the dental arch. [Figure 28] This is a perspective view of a mouthpiece according to the first embodiment of the first aspect of the present invention, as shown in Chapter 3. [Figure 29a] This figure schematically shows a partial cross-sectional view of a second embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by arrow XXVIII-XXVIII in Figure 28. [Figure 29b] This figure schematically shows a partial cross-sectional view of a second embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by arrow XXVIII-XXVIII in Figure 28. [Figure 29c]This figure schematically shows a partial cross-sectional view of a second embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by arrow XXVIII-XXVIII in Figure 28. [Figure 30] This figure schematically shows a top view of a third embodiment of the mouthpiece according to the first aspect of the present invention as described in Chapter 3. [Figure 31a] This figure schematically shows a partial cross-sectional view of a third embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by the arrow XXX-XXX in Figure 30. [Figure 31b] This figure schematically shows a partial cross-sectional view of a third embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by the arrow XXX-XXX in Figure 30. [Figure 31c] This figure schematically shows a partial cross-sectional view of a third embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by the arrow XXX-XXX in Figure 30. [Figure 32a] This figure provides an explanation of the second aspect of the present invention in Chapter 3, and an explanation of the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 32b] This figure provides an explanation of the second aspect of the present invention in Chapter 3, and an explanation of the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 32c] This figure provides an explanation of the second aspect of the present invention in Chapter 3, and an explanation of the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 32d]This figure provides an explanation of the second aspect of the present invention in Chapter 3, and an explanation of the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 33a] This diagram illustrates a recessed wall that is not locally deformable. [Figure 33b] This diagram illustrates a recessed wall that is not locally deformable. [Figure 34a] This figure provides a further explanation of the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 34b] This figure provides a further explanation of the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 35] This figure provides another further explanation of the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 36a] This figure schematically shows a partial cross-sectional view of the first embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of the different operating states. [Figure 36b] This figure schematically shows a partial cross-sectional view of the first embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of the different operating states. [Figure 36c] This figure schematically shows a partial cross-sectional view of the first embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of the different operating states. [Figure 37a] This figure schematically shows a partial cross-sectional view of the second embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of the different operating states. [Figure 37b] This figure schematically shows a partial cross-sectional view of the second embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of the different operating states. [Figure 37c] This figure schematically shows a partial cross-sectional view of the second embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of the different operating states. [Figure 38]This figure schematically shows a mesh structure according to the first embodiment of the third aspect of the present invention as described in Chapter 3. [Figure 39a] This figure schematically shows a mesh structure according to the second embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 39b] This figure schematically shows a mesh structure according to the second embodiment of the fourth aspect of the present invention as described in Chapter 3. [Figure 40a] This figure schematically shows a mesh structure according to the third embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 40b] This figure schematically shows a mesh structure according to the third embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 41a] This figure schematically shows a mesh structure according to the fourth embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 41b] This figure schematically shows a mesh structure according to the fourth embodiment of the fourth aspect of the present invention as described in Chapter 3. [Figure 42a] This figure schematically shows a mesh structure according to the fifth embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 42b] This figure schematically shows a mesh structure according to the fifth embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 43a] This figure schematically shows a mesh structure according to the sixth embodiment of the fourth aspect of the present invention as described in Chapter 3. [Figure 43b] This figure schematically shows a mesh structure according to the sixth embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 44] This diagram schematically shows the details, including the flexible recessed wall. [Figure 45] This figure schematically illustrates the dental cleaning device according to the present invention, including the mouthpiece, as described in Chapter 3. [Modes for carrying out the invention] 【0061】 [Detailed explanation of the diagram in Chapter 1] Figures 1 to 20 illustrate several embodiments of the present invention as described in Chapter 1. While the embodiments may differ, the same reference numerals / symbols will be used throughout all of these Figures 1 to 20 for the same or similar items. 【0062】 Figure 1 shows a very schematic perspective view of a portion of the upper dental arch 1 with dental positions 2–14. Each dental position is indicated by a vertical dashed line. Each dental position includes a tooth, typically named according to a nomenclature known to the dentist. Using this nomenclature: - Dental position 2 is the position of the left "second molar" as shown in Figure 1; - Dental position 3 is the position of the left "first molar," which is missing in Figure 1; - Dental position 4 is the position of the left "second premolar," as shown in Figure 1; - Dental position 5 is the position of the left "first premolar" as shown in Figure 1; - Dental position 6 is the position of the left "canine tooth" as shown in Figure 1; - Dental position 7 is the position of the left "lateral incisor," which is missing in Figure 1; - Dental position 8 is the position of the left central incisor, as shown in Figure 1; - Dental position 9 is the position of the right central incisor, as shown in Figure 1; - Dental position 10 is the position of the right "lateral incisor" as shown in Figure 1; - Dental position 11 is the position of the right "canine tooth" as shown in Figure 1; - Dental position 12 is the position of the right "first premolar" as shown in Figure 1; - Dental position 13 is the position of the right "second premolar" as shown in Figure 1; - Dental position 14 is the position of the right "first molar" as shown in Figure 1; Figure 1 does not show the dental position of the right "second molar," nor the dental positions of the right and left "third molars" (also called wisdom teeth). Similarly, the mandible has a similar number of dental positions, which are similarly named according to the aforementioned nomenclature. 【0063】 Reference numeral 15 indicates the lingual side of the arc of dental position. The lingual side 15 is the inner side of the arc of dental position, and the inner side faces the tongue. Reference numeral 16 indicates the facial side of the arc of dental position. The facial side 16 is the outer side of the arc of dental position, and the outer side faces the face, such as the cheeks and lips. 【0064】 Figure 1 further illustrates a system of three mutually orthogonal axes, including the x-axis X, y-axis Y, and z-axis Z. The z-axis Z is a curved axis following the contour of the dental arch 1. The x-axis X and y-axis Y are perpendicular to each other and define the xy-plane, which is essentially flat and perpendicular to the dental arch 1; that is, each xy-plane intersecting at a given point on the z-axis is perpendicular to the curved z-axis Z at that point. The z-axis Z defines the curved longitudinal direction. The z-axis Z and y-axis Y define the curved zy-plane, which, when viewed along the z-axis, has an arc shape similar to the shape of the dental arch arc. Furthermore, the z-axis Z and x-axis X define the zx-plane. 【0065】 Figure 2a schematically shows a perspective view of an example of a mouthpiece 20 made by the method according to the present invention in Chapter 1. Figure 2b shows a cross-section of the mouthpiece of Figure 2a as seen by arrow IIb in Figure 2a. 【0066】 The mouthpiece 20 includes a body portion 21 provided with a first recess 22. This first recess 22 has a curved longitudinal direction when viewed along the z-axis in Figure 1 and has a U-shaped cross-section when viewed in the xy-plane in Figure 1. The first recess 22 is bounded by a recess wall 23, which is U-shaped in the xy-plane. The recess wall 23 is lined with a plurality of bristle 24, each having one end (called a root portion 19) attached to the recess wall 23 and extending from the recess wall 23 into the first recess 22. 【0067】 Reference numeral 26 indicates a nipple, which is configured to connect the mouthpiece to the pumping and / or suction device. The mouthpiece 20 further has a right half 27 and a left half 28, which these halves come together, so to speak, in the nipple 26. 【0068】 Reference numeral 25 indicates a curved dividing line, which defines a mirror plane parallel to the xz plane as defined in Figure 1. The mouthpiece shown in Figure 2 is, so to speak, mirror symmetric with respect to this mirror plane, meaning that a second recess (not visible in Figure 2a but visible in Figure 2b) exists on the opposite side of the first recess 22, and this second recess is also lined with bristle. It should be noted that since the upper and lower arcs (of the teeth) of the dental position have different shapes, the first recess can have a different shape from the second recess. 【0069】 The recess 22 is configured to encompass the entire dental arch from the dental position of the right third molar or second molar to the dental position of the left third molar or second molar, respectively. The recess 22 may also be configured to encompass a portion of the arch of dental positions, which may include at least five dental positions, for example, from the dental position of the central incisor to the dental position of the second premolar, or from the dental position of the first molar or the dental position of the second molar. 【0070】 Figure 2b shows a cross-section of the right-hand component of the mouthpiece 20, indicated by arrow IIb in Figure 2a. 【0071】 As best seen in Figure 2b, the bristle may be provided as a tuft 29 of a relatively thin bristle 24. Each tuft 29 may have a base 36, which supports the bristle 24 at its root 19 and is attached to the recess wall. 【0072】 As can be seen in Figure 2b, the mouthpiece 20 has a body portion 21, which has a first recess 22 on its upper side and a second recess 22 on its lower side. Both recesses 22 are bounded by a flexible recess wall 23. In a cross section parallel to the xy plane as defined in Figure 1, the recess wall 23 is U-shaped and has a recess wall bottom 34 and two recess wall legs 33, the two recess wall legs 33 extending from the recess bottom wall. The recess wall 23 is covered by a bristle tuft 29 over the recess wall legs 33 and / or bottom 34. 【0073】 Inside the main body is a pressure chamber 35, which can be filled with a fluid via a nipple 26 (Figure 2a). The fluid can be a gas such as air or a liquid such as water. In an embodiment as shown in Figure 2, the mouthpiece has one pressure chamber. However, it should be noted that the mouthpiece can include multiple pressure chambers, such as five pressure chambers, or any other number of pressure chambers. Unpublished Patent Document 1 shows examples of other numbers of pressure chambers in Figures 4, 5, 7, 9, and 10. In the case of multiple pressure chambers, all pressure chambers or groups of pressure chambers can be fluidly connected to each other, as described in Unpublished Patent Document 1 according to the present invention in Chapter 1. 【0074】 As can be seen in Figure 2b, the mouthpiece may include an internal support structure made of a material rigid to the material of the recess wall 23. This support structure may include a lingual plate 30 and a facial plate 32, both of which extend along the curved zy-plane defined in Figure 1, and consequently have a U-shape when viewed along the z-axis. To maintain the lingual plate 30 and the facial plate 32 at a predetermined distance from each other, the support structure may include one or more spacers 31. These one or more spacers 31 may be, for example, multiple bars or wires or a single plate, which may extend essentially parallel to the zx-plane as defined in Figure 1. In the case of a single plate as a spacer, this plate may divide the pressure chamber 35 into two pressure chambers (an upper chamber and a lower chamber). These two pressure chambers may be in fluid communication with each other through one or more through-holes through the plate. In the case of large through-holes and / or multiple through-holes, the two pressure chambers may effectively be one single pressure chamber. 【0075】 The mouthpiece shown in Figure 2 is configured to brush multiple dental locations simultaneously. If teeth are present, each dental location will be brushed. The remaining portion of a dental location, such as the gums, may be brushed if teeth are missing, and teeth adjacent to the missing tooth location may be additionally brushed by bristle designed for the missing tooth location. 【0076】 A single pressure chamber 35 includes a first flexible recess wall 23 defining the boundary of a first recess 22 (the upper one in Figure 2b) and a second flexible recess wall 23 defining the boundary of a second recess 22 (the lower one in Figure 2b). The first and second recess walls are deformable, in particular, by increasing or decreasing the pressure in the pressure chamber 35. The flexible recess walls 23 may be made from an elastic material, such as a rubber-like material. Alternatively, the flexible recess walls 23 may be made from an inelastic material. The material of the flexible recess wall 23 can maintain a predetermined shape when there is substantially no pressure difference or a low pressure difference across the inner and outer sides of the flexible recess wall 23. 【0077】 The mouthpiece 20 is configured such that the tufts 29 of the bristle 24 engage with the tooth surfaces of the dental arch, or, in the case of one or more dental positions where teeth may be missing, the tufts 29 of the bristle 24 engage with the gums at each dental position when the pressure in the pressure chamber 35 is increased. In particular, if there may be missing teeth at a given dental position, the tufts 29 of the bristle at the free end of the recessed wall leg 33 will engage with the gums at the empty dental position. 【0078】 When viewed along the longitudinal direction Z of the dental arch (as defined in Figure 1), the tufts 29 of the bristle 24 can be arranged at approximately the same density as when viewed in the cross-section shown in Figure 2b. 【0079】 When the pressure in the pressure chamber 35 is increased to an increased pressure state, for example by supplying fluid to the pressure chamber 35 or by increasing the amount of fluid in the pressure chamber 35, the recess wall 23 is so-called compacted, narrowing the recess 22, thereby allowing the bristle 24 (particularly its free end) to engage firmly with the tooth surface and / or to deform in contact with the tooth surface. When the pressure in the pressure chamber 35 is subsequently decreased, the recess wall is so-called widened, expanding the recess 22. This narrowing and widening of the recess wall may be small, but when repeated reciprocally at some frequency from 1 Hz to 50 Hz, for example, the reciprocal deformation of the recess wall by reciprocating narrowing and widening the recess wall moves the bristle between a firmer engagement with the tooth surface and a relatively looser engagement, and / or alternates the bristle between a first and second deformed state, which causes sweeping and / or rubbing of the bristle along the tooth surface. It should also be noted that the recessed walls obtained by the method according to the present invention in Chapter 1 can also be used in other types of mouthpieces, such as mouthpieces without a pressure chamber. The recessed walls obtained by the method according to the present invention in Chapter 1 can be used, for example, in a mouthpiece in which the mouthpiece as a whole is mechanically vibrated to cause the bristle to perform a brushing motion. 【0080】 An effective brushing action of the mouthpiece can be obtained by appropriate cycles of increasing and decreasing the pressure in the pressure chamber 35. The bristle 24 attached to the bottom of the recess wall 34 generally performs upward and downward motion during such cycles, while the bristle 24 at the leg of the recess wall 33 generally performs lateral motion back and forth in the x-axis direction as defined in Figure 1 during such cycles. Due to the alternate narrowing and widening of the recess 22 as the pressure is reciprocally increased and decreased, the bristle 24 at the leg of the recess wall may also be subjected to pivoting back and forth around the z-axis as defined in Figure 1, resulting in sweeping and / or rubbing motion of the bristle in the y-axis direction as defined in Figure 1. 【0081】 Referring to Figure 1, the width of the tooth elements in the X direction varies between approximately 2 mm and 12 mm depending on the dental position. Considering the desire to keep the mouthpiece as small as possible, the internal width of the U-shaped recess wall in the X direction should be kept as small as possible, and can be approximately 0 mm to 2 mm wider than the width of each tooth. As an example to give some indication of the dimensions, the internal width of the U-shaped recess wall can range from 0 mm to 20 mm when viewed in the X direction in Figure 1, and can range, for example, from 2 mm to 12 mm. The bristle can be up to 6 mm in length. In the example, the bristle is 3 mm to 4 mm in length. This means that there is no gap remaining between the bristles extending from the opposing recess wall legs 33, or a limited amount of gap of approximately 2 mm to 4 mm remains. In Figure 2, these gaps are shown in an exaggerated manner. Furthermore, as an example to provide some indication of dimensions, the U-shape of the recessed wall can have an internal height ranging from 3 mm to 20 mm when viewed in the Y direction in Figure 1, for example, from 5 mm to 10 mm. These internal width and internal height measurements are given for adults. These measurements may differ for children or animals. This limited amount of space makes it difficult to manufacture mouthpieces as shown in Figure 2 in an economical manner. For example, injection molding is difficult due to the fact that the bristle extending from the opposing recessed wall legs essentially extends in the X direction (the X direction being transverse to the direction in which injection molded molds can be separated from each other after molding). 【0082】 Figure 3 schematically illustrates the first method according to the present invention in Chapter 1, where Figure 3a shows a sheet 100 having a bristle-lined sheet component 101 lined by a bristle 104 on one side 102, Figure 3b shows a mold 110 for plastically deforming the bristle-lined sheet component 101, Figure 3c shows the bristle-lined sheet component 101 lying on the mold 110 before plastic deformation, Figure 3d shows the bristle-lined sheet component 101 after plastic deformation, and Figure 3e shows an enlarged detail IIIe of Figure 3d, where Figure 3c is the left half of axis 107 and Figure 3d is the right half of axis 107. 【0083】 Figure 3a shows a sheet 100, which may be made from a thermoplastic elastomer. The bristle-equipped sheet component 101 of this sheet 100 is indicated by an inner dashed arc 105 and an outer dashed arc 106. The shapes of these arcs 105 and 106 can correspond to the shapes of the arcs in a dental position as shown in Figure 1. The sheet 100 and the bristle-equipped sheet component 101 have a first side 102 (upper side in Figure 3) and an opposing second side 103 (lower side in Figure 3). The first side 102 of the bristle-equipped sheet component 101 is lined with a bristle 104. In Figure 3 (which is schematic), the bristle 104 is shown on the left half of the bristle-equipped seat component 101, but it should be noted that in reality, the right half of the bristle-equipped seat component 101 and the upper part of the bristle-equipped seat component 101 are also covered by the bristle 104. 【0084】 Figure 3a shows the bristle-covered sheet part 101 obtained in the providing step. In this providing step, the bristle-covered sheet part 101 is in its initial state. As shown in Figure 3a, in the initial state, the bristle 104 all extend in the same upward direction. In the initial state, the bristle 104 can be essentially parallel to one another. In this initial state, the bristle-covered sheet part 101 has a cross-sectional shape called the “initial shape” when viewed in the xy-plane as defined in Figure 1, and has an arched length axis when viewed along the z-axis as defined in Figure 1. In Figure 3a, the bristle-covered sheet part 101 is shown as part of the sheet 100, but it should be noted that the rest of the sheet outside the dashed arcs 105 and 106 may not exist, for example, it may have been cut off. In this case, only the arc-shaped bristle-covered sheet part 101 would exist, and the rectangular sheet 100 containing the bristle-covered sheet part 101 would not exist. 【0085】 In the initial state shown in Figure 3, the "initial shape" of the cross-section of the bristle-equipped seat component 101 is flat. However, the initial shape of the first side portion 102 of the bristle-equipped seat component 101 may be concave (with the second side portion 103 being convex) or convex (with the second side portion 103 being concave). 【0086】 Figure 3b shows a mold 110 for transforming the bristle-equipped sheet component 101 by thermoforming it from the initial state to the final state as shown in Figure 3a. The mold 110 has a cavity 111 on its upper side portion 118, which is U-shaped in the xy plane as defined in Figure 1 (see also reference numeral 112), and the cavity 111 extends along an arc similar in shape to the arc of the dental position in the z direction as defined in Figure 1. Several suction openings 113 can open into this cavity 111 (only one suction opening is shown in Figure 3b, but multiple can be distributed across the cavity 111). The cavity has an arc-shaped inner edge portion 115 and an arc-shaped outer edge portion 116 on its upper side portion. 【0087】 Figure 3c is the left half of axis 107, showing sheet 100 lying on mold 110, with bristle sheet part 101 overlapping cavity 111. The inner arc 105 and outer arc 106 can lie above the inner edge 115 and outer edge 116 of the cavity, respectively. However, the inner arc 105 and outer arc 106 can have a greater distance than the inner edge 115 and outer edge 116 when viewed in the x direction in Figure 1, resulting in the inner arc 105 and outer arc 106 lying above the upper surface 118 of mold 110. 【0088】 Starting from the state shown in Figure 3c, a suction force can be applied to the cavity 111 through the suction opening 113 or otherwise. This suction force will transform the bristle-seat component 101 by thermoforming it from its initial state shown in Figures 3a and 3c to its final state shown in Figures 3d and 3e, providing a recessed wall 120 (see also Figure 4), which may be used as the recessed wall 23 in the embodiment of Figure 2. In this final state, the cross-sectional shape of the bristle-seat component 101 is a final U-shape, the length axis is (still) arched, and the first side is the concave inner side of the final U-shape. In the initial state, the first side may already be concave, and in the final state, the first side of the bristle-seat component 101 will be more concave than in the initial state. 【0089】 When the bristle-covered sheet part 101 is plastically deformed, the bristle-covered sheet part 101 can be stretched when viewed in the direction along the U-shaped contour. If it is desired to have a uniform distribution of bristle when viewed in the final state and in the direction along the U-shaped contour, this stretching can be taken into consideration when providing the bristle-covered sheet part in the providing step by providing the bristle with a higher density and, optionally, with a non-uniform distribution (the non-uniform distribution is configured to be converted to a uniform distribution during the transformation step). 【0090】 Referring to Figures 3e and 2b, the final U-shape is defined by two leg components 33 and a base component 34 connecting these leg components, with the vertical axis 119 defined as extending between the leg components 33. 【0091】 For clarity, Figure 3d schematically shows only the bristle 104 at three locations. However, it will be clear that the entire recess wall will be covered by the bristle. This can be, for example, a series of continuous U-shaped bristle arcs, as shown in detail in Figure 3e, when viewed along the z-axis defined in Figure 1. As can be seen in Figures 3d and 3e, the bristle 104 on one leg component 33 and the bristle 104 on the other leg component 33 extend toward each other from their respective leg components 33. 【0092】 As can be seen in Figure 3a, the bristle-covered sheet component is a continuous sheet component. It does not have cutouts that facilitate the transformation of the bristle-covered sheet component 101 from the initial state (Figure 3a) to the final state (Figures 3d and 3e). 【0093】 Figure 4 shows a recessed wall manufactured according to the method of the present invention in Chapter 1, for example, a recessed wall 120 obtained by the method according to Figure 3. Similar to Figure 3d, the bristle 104 is shown only at the ends and in the middle of the recessed wall, but the inner side of the recess, which is bounded by the recessed wall when viewed along the Z-axis as defined in Figure 1, can be completely covered by the bristle 104. 【0094】 Figure 5 shows a “further providing step” of the method according to the present invention in Chapter 1. In this “further providing step,” a lingual frame member 121 and a facial frame member 122 are provided. Both the lingual frame member 121 and the facial frame member 122 are arched in shape and both have upper edges 125 and 126, respectively. Referring to Figure 2b, the lingual frame member 121 can correspond to the lingual plate 30, and the facial frame member 122 can correspond to the facial plate 32. 【0095】 As indicated by the thick arrow A between Figure 4 and Figure 5, the recessed wall 120 can be fixed to the lingual frame member 121 and the facial frame member 122 during the fitting step. For this purpose, the inner edge 105 of the recessed wall 120 (= the inner arc of the dashed line in Figure 3) is fixed to the upper edge 125 of the lingual frame member 121, and the outer edge 106 of the recessed wall 120 (= the outer arc of the dashed line in Figure 3) is fixed to the upper edge 126 of the facial frame member 122. This results in the illustration in Figure 6. After the gap between the lower edge 123 of the lingual frame member 121 and the lower edge 124 of the facial frame member 122 is closed by the closure 127, the mouthpiece according to the present invention of Chapter 1 is obtained comprising the facial frame member 122, the recessed wall 120, the lingual frame member 121, and a pressure chamber bounded by the closure. When the vertical lengths of the lingual frame member 121 and the facial frame member 122 are extended in the direction of the y-axis, as shown in Figures 1 and 4, the closure can be a further recessed wall, which is oriented so that its opening faces downward. Thus, a mouthpiece like the one shown in Figure 2 is obtained. As shown in Figure 2b, the outer surfaces of the lingual frame member and the facial frame member can be coated, for example, in an injection molding process with the same material as the bristle-equipped sheet component. 【0096】 As indicated by arrow V in Figure 6, the curvature of the tongue-side frame member 121 and the face-side frame member 122 can be reduced, for example, by compressing the free ends of the arch-shaped frame members after the recessed walls 120 have been fitted to these frame members. Doing so will result in an increase in the depth of the U-shaped cross-section when viewed in the direction of the Y axis in Figures 1 and 4, in other words, the bottom of the U-shaped cross-section will be closer to the closure 127. This can be used to transform the bristle-covered sheet part 101 to its final state in addition to, or as an alternative to, the thermoforming transformation of the method in Figure 3. When used as an alternative to thermoforming, the bristle-covered sheet part 101 can still be flat or slightly curved (similar to Figure 3a) when in the state shown in Figure 6. Next, the transformation step includes transforming the cross-sectional shape from its flat or slightly curved initial shape to its final U-shape, while simultaneously reducing the initial curvature of the bristle-equipped sheet part 101 to its final curvature. 【0097】 Referring to Figure 6, the curvature of the lingual frame member 121 and the facial frame member 122 can also be realized by using elastic frame members 121 and 122. From a released or stress-free state (in which the frame members have a narrow arc curve corresponding to their final curvature), the frame members 121 and 122 can be pre-biased from the released state to a pre-tensioned state (in which the frame members have a wider arc curve than in the released state, and this wider arc curve can correspond to the initial curvature of the bristle-equipped seat component). In this pre-tensioned state, the frame members 121 and 122 have pre-tension acting in the direction of returning the frame members 121 and 122 to their released state (which can correspond to the final state). 【0098】 Figure 7b shows a diagram similar to that of Figure 6. Figure 7a shows a side view indicated by arrow VIIa in Figure 7b. Figure 7a shows the bristle-equipped sheet part 101 in its initial state as it is obtained in the providing step. In this initial position, the bristle-equipped sheet part 101 is flat, however the first side lined by the bristle 104 may be shallowly concave or convex. Figure 7b shows the bristle-equipped sheet part 101 in its final state. By moving the inner edge 105 and the outer edge 106 toward each other, as indicated by arrow C in Figure 7b, the bristle sheet component 101 is transformed from the initial state shown in Figure 7a to the final state shown in Figure 7b by reducing the distance between the inner edge 105 (=inner arc of the dashed line in Figure 3) and the outer edge 106 (=outer arc of the dashed line in Figure 3) of the bristle sheet component 101 from a wider d2 (see Figure 7a) to a smaller d1 (see Figure 7b) when viewed in the x-axis direction as defined in Figure 1 and also shown in Figure 4. Doing so results in an increase in the depth of the U-shaped cross-section when viewed in the Y-axis direction in Figures 1 and 4. This can be used in addition to or as an alternative to thermoforming, to transform the bristle-covered sheet component 101 into its final state. When used as an alternative to thermoforming, the bristle-covered sheet component 101 can still be flat or slightly curved (as shown in Figure 7a) when it is in the state shown in Figure 7a. If the bristle-covered sheet component 101 is attached to the upper edges of the frame members 121 and 122, the transformation step can be carried out by reducing the distance between the face-side frame member 122 and the tongue-side frame member 121 in the x-axis direction (as defined in Figure 1 and as shown in Figure 4). 【0099】 The mechanisms described above in relation to Figures 6 and 7 (in short, shown as the V-mechanism (Figure 6) and the C-mechanism (Figure 7)) are both essentially mechanical transformations. Furthermore, the V-mechanism and the C-mechanism can be used in combination, one after the other, or simultaneously, as shown in Figure 8. In Figure 8, Figure 8a shows an initial state having an arched length axis L1 and a distance d1 between the inner edge 105 and the outer edge 106 of the bristle-equipped sheet component 101, and Figure 8b shows a final state having an arched length axis L2 and a distance d2 between the inner edge 105 and the outer edge 106 of the bristle-equipped sheet component 101, where d2 is smaller than d1 and L2 has a stronger / narrower curvature than L1. 【0100】 Figure 9 shows an example in which two sheet components 101 are provided as a single component 150. Figure 9a shows the single component in a flat state. This single component includes two bristle sheet components 101 having a first side lined with bristle, the bristle on this first side being shown as a gray, arc-shaped surface. The two bristle sheet components are connected by a transition area 151. These transition areas 151 are configured to allow the two bristle sheet components 101 to fold relative to each other from a first position to a second position, in which the two bristle sheet components 101 are aligned (this first position is shown in Figure 9a), and in the second position, the two bristle sheet components are folded relative to each other (this second position is shown in Figure 9b). In the supplying step, the single component 150 may be supplied in the state shown in Figure 9a, or in the state shown in Figure 9b, or in any intermediate state between the state in Figure 9a and the state in Figure 9b. If the single component 150 is supplied in the state in Figure 9a or the intermediate state, the bristle-equipped sheet component 101 may be folded in the folding step from a first position (Figure 9a or an intermediate state between Figure 9a and Figure 9b) to a second position (Figure 9b). 【0101】 Figure 10 shows cross-sectional views of the bristle-equipped seat component 101 in its initial state (Figure 10a) and further examples of the bristle-equipped seat component 101 in its final state (Figure 10b). The first side portion 102 of the bristle-equipped seat component 101 is slightly concave in the initial state. The bristle-equipped seat component 101 has two leg components 33 interconnected by a bottom component 34. The vertical axis 160 extends transversely with respect to the bottom component 34. In the initial state, the bristle 104 extends parallel to the vertical axis 160. The angle α of the leg components 33 with respect to the vertical axis 160 can be, for example, 55° in the initial state. In the transformation step, when the leg components 33 are rotated toward each other by an angle of x° with respect to the vertical axis 160, the resulting angle of the leg components 33 with respect to the vertical axis will be α-x°, and the angle of each bristle on the leg components 33 with respect to the vertical axis will be x° (see Figure 10b). Assuming that x can be 45° and α can be 55°, the final angle α-x° of the leg components 33 with respect to the vertical axis 160 will be 10°. 【0102】 With respect to Figure 10, it should be noted that although the base component 34 does not show a bristle, the bristle 104 may similarly be present on top of the base component 34. Furthermore, for the sake of simplification and for the sake of explaining Figure 10, the leg components 33 are shown as straight, but it should be noted that these leg components 33 may similarly be curved in Figures 10a and 10b, or they may start straight in Figure 10a and become curved in Figure 10b. 【0103】 Figure 11 schematically illustrates the effects of both narrowing the curvature of the longitudinal axis of the bristle-equipped sheet component 101 and reducing the mutual distance d between the boundary edges 105 and 106 of the bristle-equipped sheet component 101, i.e., the distance d between the inner edge 105 and the outer edge 106, in the transformation step through an essentially mechanical transformation of the bristle-equipped sheet component 101. Figure 11a shows a perspective view of the non-bristle side of the bristle-equipped sheet component 101 in its initial state, and Figure 11b shows a perspective view of the non-bristle side of the bristle-equipped sheet component 101 in its final state. As can be seen from Figures 11a and 11b, the initial wide curvature of the longitudinal axis of the bristle-equipped sheet component 101 (see Figure 11a) is less curvature than the final narrow curvature of the longitudinal axis of the bristle-equipped sheet component 101 (see Figure 11b). Figure 11c shows the cross-sectional shape of the bristle sheet component 101 at location m, in the initial state (left side) and in the final state (right side). Figure 11d shows the cross-sectional shape of the bristle sheet component 101 at location n, in the initial state (left side) and in the final state (right side). Figure 11e shows the cross-sectional shape of the bristle sheet component 101 at location o, in the initial state (left side) and in the final state (right side). As can be seen from Figures 11c, 11d, and 11e, the distance between boundary edges 105 and 106 is reduced from d1 in the initial state to a smaller d2 in the final state. This transformation can be carried out without stretching the sheet component 101. When carrying out this transformation, it is noted that narrowing the curvature of the length axis and reducing the distance between them can occur simultaneously. As illustrated in Figure 11c, the cross-sectional shape at position o changes from a relatively shallow, blunt U-shape to a relatively deep, sharp U-shape (like a V-shape). As illustrated in Figures 11d and 11e, the cross-sectional shapes at positions m and n change from a relatively shallow U-shape to a relatively deep U-shape.Positions m and n are located on the relatively straight part of the arched bristle seat component, while position o is located on the relatively most curved part of the arched bristle seat component. In the final state (shown in Figure 11b, as well as on the right-hand component in Figures 11c, 11d, and 11e), and viewed from position m to position o, the change in cross-sectional shape from a blunt U-shape to a sharp U-shape (V-shape) corresponds to the change in cross-sectional shape of the human dental arch. In the human dental arch, the central and lateral incisors can have a roughly V-shaped cross-section when viewed in a plane perpendicular to the length of the human dental arch, the molars and premolars have a roughly U-shaped cross-section, while the canines have a cross-section between V-shape and U-shape. 【0104】 Figures 12 to 18 schematically illustrate some further examples of embodiments of the present invention according to Chapter 1. All of these figures are cross-sectional views (in the xy-plane as defined in Figure 1) with respect to the longitudinal axis of the arch shape (extending in the direction of the z-axis in Figure 1). The cross-sectional views in Figures 12 to 18 are taken at position m in Figure 11. Similar to Figure 11, the longitudinal axis of the bristle-equipped sheet component 101 shown in Figures 12 to 18 is arch-shaped, and similar to Figure 11, the cross-sectional shape of the bristle-equipped sheet component 101 shown in Figures 12 to 18 can be varied along the longitudinal axis of the arch shape in the final state. 【0105】 The embodiment in Figure 12 schematically shows an example of a relatively thick bristle-equipped sheet part 101 processed into a mouthpiece by the method according to the present invention in Chapter 1. Figure 12a shows the bristle-equipped sheet part 101 in its initial state, as provided by the steps provided. The thickness of the sheet part is defined as the thickness of the sheet part itself, without taking into account the bristle on the sheet part, and is indicated by g in Figure 12a. In the example in Figure 12, the thickness g is approximately 15 mm, whereas in the other examples in Figures 1 to 10 and Figures 12 to 18, the thickness g can be in the range of, for example, 0.5 mm to 3 mm. Figure 12b shows the bristle-equipped sheet part 101 after transformation to the final state (i.e., the resulting recessed walls). Figure 12c shows the two recessed walls joined together with their U-shaped bottoms facing each other. The U-shaped bottom is then joined together at 130, for example, by heat welding or by adhesive (or glue), resulting in a mouthpiece as shown in Figure 12d. The mouthpiece shown in Figure 12d can be used for brushing teeth, for example, by mounting the mouthpiece on a rod (the rod may be attached to the mouthpiece at location o in Figure 11b), and by exposing the rod to vibrational movement in the longitudinal direction of the rod and / or in one or two mutually perpendicular directions (each perpendicular to the rod). 【0106】 The embodiment in Figure 13 schematically illustrates, through two modifications, an example of a bristle-equipped sheet component assembly 201 machined into a recessed wall by the method according to the present invention in Chapter 1. The sheet component assembly 201 includes a bristle-equipped sheet component 101 bounded by an inner arc / (wall) edge 105 and an outer arc / (wall) edge 106 in the direction of the longitudinal axis of the arch shape. The sheet component assembly 201 further includes an inner mounting member 231 extending along the entire inner boundary edge 105, and an outer mounting member 232 extending along the entire outer boundary edge 106, on the outer boundary edge 106. Additionally, the sheet component assembly 201 further includes a tongue-side frame member 30 and a face-side frame member 32. The inner mounting member 231 and the outer mounting member 232 may be shaped as side flaps protruding from the inner boundary edge 105 and the outer boundary edge 106, respectively, as shown in Figure 13. The lingual frame member 30 and the facial frame member 32 may be shaped as plates, as shown in Figure 13. 【0107】 The sheet component assembly 201 in Figure 13 may be provided in the providing step as a prefabricated part in the initial flat state of Figure 13a, or in the initial U-shaped state of Figure 13b, or in the initial state in which the flaps 231, 232 and plates 30, 32 have any other positions relative to and / or to the bristle-equipped sheet component 101. The prefabricated part may be manufactured, for example, by injection molding (e.g., multi-material injection molding technique). Alternatively, the sheet component assembly in Figure 13 may be manufactured, for example, by injection molding (e.g., multi-material injection molding technique) during the providing step. 【0108】 Whether the sheet component assembly 201 is a pre-fabricated part manufactured before the providing step or manufactured during the providing step, in both cases it may be manufactured by injection molding (e.g., multi-material injection molding technique). A tuft 29 with a bristle 24 (optionally pre-assembled) is placed as an insert in the injection molding mold, and the base of the tuft (optionally, a base 36 may be provided for each tuft as shown) protrudes into the mold cavity where the sheet part 101 will be formed. After the mold is closed, the first and second plastic materials are injected into the mold. The first material forms the tongue-side frame member 30 and the face-side frame member 32, and the second material forms the sheet part 101 and the inner mounting member 231 and the outer mounting member 232. At the interface 250 between the frame members 30, 32 and the mounting members 231, 232, the frame members 30, 32 and the mounting members 231, 232 will bond to each other due to the fused interface layer formed therein. The second material forming the sheet component 101 is overmolded with the tuft base 36, creating a firm bond between the tuft and the sheet component 101. The bond between the base 36 and the sheet component may result, for example, from the base being enclosed within the sheet component, and / or from fusion at the interface between the second material and the base 36. Alternatively, the tongue-side frame member and the face-side frame member may be prefabricated and, like the tuft, placed as inserts into the injection mold. In this case, only the second material for forming the sheet component and the mounting member is injected, and this material is overmolded with the mounting member, bonding to the mounting member by forming a fused interface layer. 【0109】 In the providing step, the sheet component assembly 201 obtained in the initial state shown in Figure 13a or Figure 13b, for example, then undergoes a transformation step. In this transformation step (which can be, for example, by thermoforming and / or mechanical deformation (e.g., by narrowing the curvature of the length axis of the sheet component and / or by reducing the distance between the inner boundary edge 105 and the outer boundary edge 106)), the sheet component assembly 201 is transformed into its final state as shown in Figure 13c. In the embodiment of Figure 13, the transformation step is performed by thermoforming. However, as mentioned above, it can be performed by two modes of mechanical deformation or a combination of these two modes, and thermoforming and mechanical deformation can be combined in the transformation step. 【0110】 As can be seen in Figure 13c, the tufts 29 / bristle 24 are distributed in a regular pattern when viewed in the cross-sectional plane. Similarly, in Figures 13a and 13b, the tufts 29 / bristle 24 are distributed in a regular pattern. Due to the stretching of the wall component 101 during the transformation steps, the distances between the tufts 29 / bristle 24 are increased in Figure 13c compared to Figures 13a and 13b. In this example, this stretching is regular across a U-shape, but it may be irregular. Taking the stretching into account, the tufts / bristle may be arranged in the initial state of Figures 13a and 13b, and in the final state of Figure 13c, the tufts / bristle have a predetermined distribution (like a regular distribution). 【0111】 The embodiment in Figure 14 schematically shows another example of a bristle-equipped sheet component assembly 201 with a recessed wall fabricated by the method according to the present invention in Chapter 1. This embodiment is essentially the same as the embodiment in Figure 13, except that in the embodiment of Figure 14, the bristle is injection-molded from the same material as the sheet component, instead of a tuft being inserted into the injection molding mold before injection molding. With respect to the remainder, the commentary given in relation to Figure 13 also applies to Figure 14, with modifications where necessary. 【0112】 The embodiment in Figure 15 schematically shows another example of a bristle-equipped sheet component assembly 201 with a recessed wall fabricated by the method according to the present invention in Chapter 1. Although Figure 15 is shown with a tuft as in Figure 13, it can also work just as well with an injection-molded bristle 24 as in Figure 12. The main difference between the embodiment in Figure 15 and the embodiments in Figures 13 and 14 lies in the inner and outer mounting members. 【0113】 In Figure 15, the inner and outer mounting members are formed as double-sided flaps extending along the inner boundary edge 105 and the outer boundary edge 106, respectively. The inner mounting member includes a first flap component 231 and a second flap component 233, the second flap component 233 being parallel to the first flap component 231 and at a predetermined distance from the first flap component 231, such that a gap 235 is defined between the inner flap component 231 and the outer flap component 233. As indicated by the arrow in Figure 15b, the tongue-side frame plate 30 can be inserted into this gap 235. Similarly, the outer mounting member includes a first flap component 232 and a second flap component 234, the second flap component 234 being parallel to the first flap component 232 and at a predetermined distance from the first flap component 232, such that a gap 236 is defined between the inner flap component 232 and the outer flap component 234. As indicated by the arrow in Figure 15b, the face-side frame plate 32 can be inserted into this gap 235. 【0114】 Figure 15a shows the initial state of the seat component assembly 201 obtained in the providing step (frame members 30 and 32 are not yet included). Figures 15b and 15c show the final state of the seat component assembly 201. As can be seen from Figure 15b, first the transformation step is applied to the seat component assembly of Figure 15a without the frame members 30 and 32, and then the tongue-side frame member 30 and face-side frame member 32 are inserted into the respective gaps 235 and 236. The frame members 30 and 32 can be attached to the outer flaps 231, 232 and inner flaps 233, 234 by adhesive (or glue) and / or by heat welding. 【0115】 With respect to the embodiment shown in Figure 15, it should be noted that this embodiment may also be manufactured by a combination of injection molding techniques as described in relation to Figure 13, or, if the bristle is as shown in Figure 14, by a multi-material injection molding technique (in which case the seat component, flap, and frame member are injection molded simultaneously or sequentially in a single mold), or by overmolding (in which case the frame member is manufactured before the seat component and flap are molded (or conversely, before the seat component and flap are molded)). 【0116】 The embodiment in Figure 16 schematically shows another example of a bristle-equipped seat component assembly 201 processed into a mouthpiece with a recessed wall according to the present invention in Chapter 1, by the method according to the present invention in Chapter 1. The embodiment in Figure 16 is essentially the same as the embodiment in Figure 14, and the explanation relating to Figure 14 (and Figure 13) applies similarly to Figure 16 with modifications where necessary. It should also be noted that the embodiment in Figure 16 can use the double-sided flap of Figure 15, and the explanation relating to Figure 15 applies similarly to Figure 16 with modifications where necessary. The differences between the embodiment in Figure 16 and the embodiments in Figures 13-15 are in the lingual frame member 30 and the facial frame member 32. These frame members provide snap connections that allow two seat component assemblies 201 to be connected together. 【0117】 Figure 16a shows one of these sheet component assemblies in its initial state. Figure 16b shows both sheet component assemblies 201 in their final state. The sheet component assemblies shown in Figure 16a and the upper half of Figure 16b carry female snap-connection parts 237, 238 on the free ends of the tongue-side frame member 30 and the face-side frame member 32. The sheet component assembly shown in the lower half of Figure 16b carries male snap-connection parts 239, 240 on the free ends of the tongue-side frame member 30 and the face-side frame member 32. As will be apparent, the sheet component assembly shown in the lower half of Figure 16b will initially be provided in a similar initial state to that shown in Figure 16a with respect to the upper half of Figure 16b. The male snap-connection parts 239, 240 and the female snap-connection parts 237, 238 are mated with each other so that a snap connection can be established. As will become clear, the male and / or female snap connectors shown are intended as examples and may be formed differently. 【0118】 After assembling the sheet component assembly 201 shown in Figure 16b, the mouthpiece according to the present invention in Chapter 1 is obtained. The brushing action can be achieved, for example, by exposing the entire mouthpiece to mechanical vibrations using a vibrating rod (or handle) as previously described in relation to Figure 12. Alternatively, the brushing action can be achieved by using the space demarcated by the lingual frame member 30, the facial frame member 32, and the sheet component 101 as a pressure chamber, and by reciprocally increasing and decreasing the pressure within this pressure chamber. 【0119】 The embodiment in Figure 17 schematically shows another example of a bristle-equipped seat component assembly 201 processed into a mouthpiece with a recessed wall according to the present invention in Chapter 1, by the method according to the present invention in Chapter 1. The embodiment in Figure 17 is essentially the same as the embodiment in Figure 16, and the explanation relating to Figure 16 (and Figures 13-15) applies similarly to Figure 17, with modifications where necessary. It should also be noted that the embodiment in Figure 17 may use the double-sided flap of Figure 15 and / or may have an injection-molded bristle 24, such as those in Figures 14 and 16. The difference between the embodiment in Figure 17 and the embodiment in Figure 16 lies in the lingual frame member 30 and the facial frame member 32. These frame members do not provide a snap connection that allows two seat component assemblies 201 to be connected together; rather, this connection is established in a different manner. In the embodiment shown in Figure 17, the connection is established by bonding, for example by adhesive (or glue), and / or by heat welding together the free ends of the lingual frame member 30 and the facial frame member 32, and / or the free ends of the flaps 231 and 232, and / or the respective frame members with the flaps, to obtain a joint at 251 and 252. 【0120】 The embodiment in Figure 18 schematically shows another example of a bristle-equipped seat component assembly 201 machined into a mouthpiece with a recessed wall according to the present invention in Chapter 1, by the method according to the present invention in Chapter 1. The embodiment in Figure 18 is essentially the same as the embodiments in Figures 16 and 17, and the descriptions relating to Figures 16 and 17 (and Figures 13-15) are similarly applicable to Figure 18, with modifications where necessary. It should also be noted that the embodiment in Figure 18 can use the single-sided flaps of Figures 13, 14, and 16, and / or can have an injection-molded bristle 24, such as those in Figures 14 and 16. The differences of the embodiment in Figure 18 compared to the embodiments in Figures 16 and 17 lie in the lingual frame member 30 and the facial frame member 32. These frame members do not provide a snap connection that allows two seat component assemblies 201 to be joined together, and do not require adhesive or heat welding together. In the embodiment shown in Figure 18, the connection is established by an H-shaped frame member 260, which includes a tongue-side frame plate 30 and a face-side frame plate 32 interconnected by a spacer member 31. The spacer member 31 may be a plate that is closed or provides a passage that provides a fluid connection between the upper and lower halves. Alternatively, the spacer member 31 may be formed by a plurality of rods or wires or may not be present at all. If the spacer member 31 is not present at all, only one tongue-side frame member 30 common to both bristle-equipped seat components 201 remains, and only one face-side frame member 32 common to both bristle-equipped seat components 201 remains. 【0121】 The embodiment in Figure 19 schematically illustrates a further example of a bristle-covered sheet component assembly 201 fabricated in a recessed wall by the method according to the present invention in Chapter 1. Figure 19a shows the sheet component in its initial position, and Figure 19b shows the sheet component in its final state. Figures 19a and 19b are identical to those in Figures 13b and 13c, except that the bristle-covered sheet component 101 in Figures 19a and 19b comprises two layers (a first layer 101a and a second layer 101b). The bristle-covered layer 201 in Figure 19 includes tufts 29 with nylon bristle. The first layer 101a provides a passage for each tuft so that the root of the bristle reaches (or slightly protrudes from) the back side of the first layer 101a, which is the lower side in Figures 19a and 19b. A second layer 101b is provided after the bristle tuft has been inserted into the passage. This second layer secures the bristle. Injection molding of the second layer fuses the root end of the bristle with the second layer, resulting in a reliable and firm bond. As will become clear, the bristle-attached layer 201 in Figure 19b can also be provided in a flat state, as shown in Figure 13a. Furthermore, it will be clear that the explanations relating to Figures 13a, 13b, and 13c will also apply to Figure 19, with modifications where necessary. 【0122】 The embodiment shown in Figure 20 schematically illustrates a further example of a bristle-equipped sheet component assembly 201 machined into a recessed wall by the method according to the present invention in Chapter 1. Figure 20a shows the sheet component in its initial position, and Figure 20b shows the sheet component in its final state. Figures 20a and 20b are identical to Figures 13b and 13c, except that in Figure 20a the tufts are irregularly spaced, while in Figure 20b they are regularly spaced. As shown in Figure 20a, there is a gap Sc1 between the first and second tufts from left to right, a gap Sb1 between the fourth and fifth tufts from left to right, and a gap Sa1 between the sixth and seventh tufts from left to right. As shown in Figure 20a, Sa1 can be larger than Sb1, and Sb1 can be larger than Sc1. However, the relationships between gaps Sa1, Sb1, and Sc1 may be different; for example, Sb1 may be equal to Sc1 and greater than Sa1. As shown in Figure 20b, gaps Sa1, Sb1, and Sc1 are increased to Sa2, Sb2, and Sc2, respectively. This increase may be due to the stretching of sheet component 101 during the transformation step. As shown in Figure 20b, Sa2 may be equal to Sb2 and Sc2. Sa1, Sb1, and Sc1 may have been chosen so that Sa2 becomes equal to Sb2 and Sc2 after the transformation step (taking into account the stretching of sheet component during the transformation step). 【0123】 The following clauses 1 to 39 provide examples of the inventions of Chapter 1 described above, and further aspects and embodiments of these Chapter 1 inventions: 1] A method for manufacturing a continuous recessed wall lined with bristle for a mouthpiece for simultaneous brushing of multiple dental positions, wherein the continuous recessed wall has an arched length axis and a U-shaped cross section configured to encompass the multiple dental positions when viewed transversely to the length axis, and the arched length axis has a length that is at least equal to the distance from the left second premolar to the right second premolar; The method includes a step of providing a long, continuous bristle-lined sheet component having a first side lined with a plurality of bristle, the long, continuous bristle-lined sheet component defining a length axis extending parallel to the bristle-lined sheet component, and defining a predetermined cross-sectional shape when viewed transversely to the length axis, the long, continuous bristle-lined sheet component obtained in the step of providing has an initial state, in the initial state, - The cross-sectional shape has an initial shape, - The length axis is arched; The method further includes a transformation step, in which the elongated continuous bristle-equipped sheet component obtained in the providing step is transformed into the continuous recessed wall having a final state; In the final state, - The cross-sectional shape has a final U-shape, - The length axis is arch-shaped, - The first side is the concave inner side of the final U-shape, A method in which the first side is more concave in the final state than in the initial state. 2] The method according to Clause 1, wherein in the final state, bristles from opposing sides of the U-shaped cross-section extend toward each other. 3] The method of Clause 1 or 2, wherein the final U-shape is defined by two legs and a base connecting these legs, and the vertical axis is defined to extend transversely with respect to the base between the two legs. 4] The method according to Clause 3, wherein in the final state, the bristle on one leg and the bristle on the other leg extend toward each other from their respective legs. 5] In the final state, the bristle on the two legs is provided at a predetermined angle with respect to the vertical axis, the angle being in the range of 0° to 90° with respect to the vertical axis, for example, in the range of 30° to 90°, as described in Clause 3 or 4. 6] The method according to any one of the clauses 1 to 5, wherein in the initial state, the first side of the bristle seat component is concave, flat, or convex. 7] The two legs and the base connecting them are defined by a final U-shape, with the vertical axis defined as extending transversely with respect to the base, and the two legs define a tangent to the first side of the bristle-equipped seat component at the respective roots of the bristle on the legs, the tangent extending in a plane transversely with respect to the length axis; In the initial state, the bristle extends parallel to the vertical axis; The method according to any one of Clauses 1 to 6, wherein in the transformation step, the two legs are bent toward each other, rotating their respective tangents over an angle of x° with respect to the vertical axis, so that the bristle associated with each tangent extends over an angle of x° with respect to the vertical axis in a direction away from the base. 8] The method according to Clause 7, wherein x° is in the range of 0° to 90°, for example, in the range of 30° to 60° or in the range of 40° to 50°. 9] The method according to clause 7 or 8, wherein the final angle of the two legs with respect to the vertical axis is in the range of 0° to 45°, for example, in the range of 5° to 20°. 10] An elongated continuous bristle-lined sheet component having an arched length axis and a first side lined with bristle is manufactured in the step of providing, according to any one of the claims 1 to 9. 11] The bristle has a root end, a free end, and a bristle body extending from the root end to the free end; The bristle-equipped sheet component obtained in the steps provided is produced by tufting, and tufting is, - The steps include inserting multiple nylon bristle or nylon bristle tufts through a first sheet component, such that the bristle body and free end extend from the front side of the first sheet component, and the root end protrudes from the back side of the first sheet component; - Optionally, the step of providing a second seat component by contacting the back side of a first seat component; - A step of fusing the root end of the bristle with a first seat component and / or an optional second seat component, The method described in any one of the clauses 1 to 10, including the method described in any one of the clauses 1 to 10. 12] The method according to any one of the clauses 1 to 11, wherein the bristle-equipped sheet component is transformed from an initial state to a final state by thermoforming, such as vacuum forming, in the transformation step. 13] The bristle-equipped sheet component is stretched by thermoforming, as described in Clause 12, when viewed in the direction along the U-shaped contour. 14] The method according to clause 13, wherein in the final state and when viewed in the direction along the U-shaped contour, the bristle is distributed according to a predetermined pattern. 15] The method according to clause 13 or 14, wherein in the initial state, the distribution of bristle on a bristle-equipped seat component is configured such that in the final state, and when viewed in the direction along the U-shaped contour, the bristle is distributed according to a predetermined pattern. 16] The method according to any one of the clauses 1 to 15, wherein the length axis has an initial curvature in the initial state and a final curvature in the final state, the initial curvature being wider than the final curvature. 17] The method according to any one of the clauses 1 to 15, wherein the length axis has the same curvature in the initial state as it does in the final state. 18] The bristle-equipped seat component has two boundary edges, the two boundary edges extending along the length axis at a predetermined mutual distance from each other when viewed in a transverse direction with respect to the length axis; The method according to any one of the clauses 1 to 17, wherein in the transformation step, the bristle-equipped seat component is transformed by reducing the distance between the two boundary edges. 19] - The bristle-equipped sheet component obtained in the step provided is bounded by an inner boundary edge and an outer boundary edge, the inner boundary edge and the outer boundary edge extending along the length axis at a predetermined distance from the length axis, - The bristle-equipped seat component is an integral part with the lingual frame member and the facial frame member, both of which are curved in the same shape as their respective arched curves, and - The method according to any one of Clauses 1 to 18, wherein the bristle-equipped seat component includes an internal mounting member at the internal boundary edge, the internal mounting member extends along the internal boundary edge and is attached to the lingual frame member, and the bristle-equipped seat component includes an external mounting member at the external boundary edge, the external mounting member extends along the external boundary edge and is attached to the facial frame member. 20] The steps provided are: - A substep of providing a facial-side frame member and a lingual-side frame member, - A substep of providing a bristle-equipped seat component that is integrated with an inner mounting member and an outer mounting member, separately from the facial-side frame member and the lingual-side frame member, - A substep of attaching the inner mounting member and the outer mounting member to the lingual frame member and the facial frame member, respectively, The method described in Article 19, including the method described in Article 19. 21] The method according to Clause 19, wherein in the step of providing, the bristle-equipped seat component, the facial-side frame component, and the lingual-side frame component are provided as a pre-fabricated, one-piece component. 22] The method according to any one of the clauses 19 to 21, wherein the bristle-equipped seat component, face-side frame member, and tongue-side frame member are manufactured by injection molding, such as multi-material injection molding, in the step of providing. 23] The method according to any one of the clauses 19 to 22, wherein the inner mounting member and the outer mounting member are configured as side flaps extending along the inner boundary edge and the outer boundary edge, respectively, and are configured to be attached to the lingual frame member and the facial frame member, respectively. 24] The inner mounting member and the outer mounting member are configured as double-sided flaps extending along the inner boundary edge and the outer boundary edge, respectively. The method according to any one of the clauses 19 to 23, wherein the lingual frame member and the facial frame member are configured to include plate components, and the double-sided flap includes a first flap component and a second flap component, the second flap component being parallel to the first flap component and at a predetermined distance from the first flap component, defining a gap between the first flap component and the second flap component, the gap being configured to receive the respective plate components of the lingual frame member and the facial frame member. 25] In the step provided, two bristle-equipped seat components are obtained, - Each bristle-equipped seat component is bounded by the inner boundary edge and the outer boundary edge, the inner boundary edge and the outer boundary edge extending along the length axis at a predetermined distance from the length axis, - Each bristle-equipped seat component is an integral part with the tongue-side frame member and the face-side frame member, and both the tongue-side frame member and the face-side frame member are curved in an arc shape along their respective arched curves. - Each bristle-equipped seat component includes the inner mounting member on the inner boundary edge, the inner mounting member extending along the inner boundary edge and attached to the lingual frame member, and each bristle-equipped seat component includes the outer mounting member on the outer boundary edge, the outer mounting member extending along the outer boundary edge and attached to the facial frame member, The face-side frame member associated with the first bristle-equipped seat component of the two bristle-equipped seat components is provided with a first snap-connection male or female component, and the face-side frame member associated with the second bristle-equipped seat component of the two bristle-equipped seat components is provided with the first snap-connection female or male component, respectively. The method according to any one of the claims 19 to 24, wherein a tongue-side frame member associated with the first bristle-type seat component of the two bristle-type seat components is provided with a second snap-connection male or female component, and a face-side frame member associated with the second bristle-type seat component of the two bristle-type seat components is provided with the second snap-connection female or male component, respectively. 26] In the step of providing, the arched curvature of the lingual frame member and the facial frame member obtained by the bristle-equipped sheet component is wider than the final curvature; In the transformation step, the arcuate curvature is narrowed to correspond to the final curvature, as described in any one of clauses 19 to 25. 27] The lingual frame member and the facial frame member are elastic and have a released state, in which the lingual frame member and the facial frame member are stress-free and have an arc-shaped curve corresponding to the final curvature of the recessed wall; The pre-preparation step is performed before or during the providing step; In the pre-biasing step, the tongue-side frame member and the face-side frame member are pre-tensioned from a released state to a pre-tensioned state, in which case the arc-shaped curvature of the tongue-side frame member and the face-side frame member corresponds to the initial curvature of the bristle-equipped seat component, and in which case the tongue-side frame member and the face-side frame member have pre-tension acting in the direction of returning them to their released state; In the transformation step, the arcuate curvature is narrowed by releasing the pretension of the lingual frame member and the facial frame member, as described in any one of Clauses 19 to 26. 28] The method according to any one of the claims 19 to 27, wherein in the step of providing, two bristle-equipped seat components are obtained, and the inner and outer mounting members of the first and second seat components are attached to each other, for example, by heat welding. 29] In the step of providing, the two bristle seat components are obtained as a single component having a transition area that integrally connects the first bristle seat component of the two bristle seat components with the second bristle seat component of the two bristle seat components; The method according to any one of the clauses 1 to 28, wherein the transition area is configured to allow two bristle seat components to fold relative to each other from a first position to a second position, in which the two bristle seat components are aligned, and in the second position, the two bristle seat components are folded over each other. 30] In the folding step, the bristle seat components are folded relative to each other from a first position to a second position, as described in Clause 29. 31] The method according to any one of the clauses 1 to 30, wherein the length of the length axis extends to a distance at least equal to the distance from the left first molar to the right first molar, for example, to a length at least equal to the distance from the left second molar to the right second molar. 32] The final U-shape has an internal width in the range of 0 mm to 20 mm, for example, in the range of 2 mm to 12 mm; and / or, The method according to any one of the clauses 1 to 31, wherein the final U-shape has an internal height in the range of 3 mm to 20 mm, for example, in the range of 5 mm to 10 mm. 33] The bristle-equipped sheet component has a thickness of up to 15 mm, and has a thickness in the range of, for example, 0.5 mm to 3 mm, as described in any one of Clauses 1 to 32. 34] A method for manufacturing a mouthpiece of the type comprising a body provided with at least one recess, wherein the at least one recess is defined by a recess wall lined with a plurality of bristles, the plurality of bristles extending from the recess wall into the recess, the recess wall defining an arch-shaped longitudinal axis, defining a U-shaped cross-sectional shape when viewed transversely to the longitudinal axis, and is configured to encompass a plurality of dental positions along the dental arch; A recessed wall is manufactured by a method described in any one of the clauses 1 to 33. 35] The method according to clause 34, wherein the main body further includes at least one pressure chamber configured to contain a fluid under pressure, and the main body is configured to deform a recessed wall by reciprocating the pressure in at least one pressure chamber to increase and decrease. 36] A mouthpiece obtained by the method described in Clause 34 or 35. 37] A recessed wall for a mouthpiece for brushing multiple dental positions simultaneously, the recessed wall obtained by the method described in any one of the clauses 1 to 33. 38] A mouthpiece for brushing multiple dental positions simultaneously, the mouthpiece comprising a body provided with at least one recess, the at least one recess being defined by a recess wall lined with multiple bristles, the multiple bristles extending from the recess wall into the recess, the recess wall defining an arch-shaped longitudinal axis, defining a U-shaped cross-sectional shape when viewed transversely to the longitudinal axis, and configured to encompass multiple dental positions along the dental arch; A mouthpiece in which the recessed wall is manufactured by the method described in any one of the clauses 1 to 33. 39] The mouthpiece according to Clause 38, wherein the main body further includes at least one pressure chamber configured to contain a fluid under pressure, and the main body is configured to deform a recessed wall by reciprocating the pressure in at least one pressure chamber. 【0124】 As can be seen from the above, the term “pressure chamber,” as used throughout this Chapter 1, refers to a chamber in which the pressure changes between a reduced pressure state and an increased pressure state. Both the reduced pressure state and the increased pressure state can be pressures below ambient pressure, i.e., a vacuum, defined as a pressure between 0 bar and 1 bar. Alternatively, both the reduced pressure state and the increased pressure state can be pressures above ambient pressure, or one of these pressure states can be approximately ambient pressure, while the other is either below or above ambient pressure. 【0125】 In this Chapter 1, where the term “pressure in a pressure chamber” or similar terminology is used, it refers to “pressure of the fluid in a pressure chamber.” It is the pressure of the fluid acting on the recessed wall, causing local deformation. The fluid pressure can be increased, for example, by supplying additional fluid into the pressure chamber, or decreased by allowing the fluid to leave the pressure chamber. 【0126】 In this Chapter 1, when "thermal welding" is used, it can refer to a thermal welding technique. - Here, heat is generated by mechanical movement, such as vibration welding and ultrasonic welding. - Techniques that use an external heat source, such as hot plate welding, hot bar welding, and hot gas welding, generate heat. - Heat is generated by techniques that use electric and / or magnetic fields, such as laser welding, infrared welding, induction welding, and dielectric welding; - Here, welding occurs during the molding of plastic or thermoplastic materials, for example, in injection molding or during compression molding. 【0127】 Where the term multi-material injection molding is used in this Chapter 1, it can refer to any injection molding technique in which an item is made from two or more injection-molded materials that fuse together at an interface to form a single part. These materials may be injected into the mold simultaneously or sequentially. Additionally or alternatively, a sub-item may be pre-fabricated by injection molding a first material into a first mold cavity and then added as an insert into a second mold cavity, where the second material is injected into the second mold cavity and becomes integral with the sub-item, and the first and second mold cavities may be located in one mold or in different molds. Many of these injection molding techniques are known to those skilled in the art and are frequently referred to under various names relating to the same or very similar multi-material injection molding techniques (e.g., multi-shot component injection molding (with two or more components), multi-component injection molding, co-injection molding, and overmolding). It should be noted that the term "component," which is frequently used in these names, means the same thing as "material." 【0128】 In this Chapter 1, where the technical term “bristle seat component” is used, it refers to a seat component having a first side lined with multiple bristles. 【0129】 In this Chapter 1, when the terms “wide,” “narrow,” “to widen,” and “to narrow” are used in relation to curvature, “wide” refers to a wide bend, similar to a wide turn when driving a car, and “narrow” refers to a narrow bend, similar to a narrow or sharp turn when driving a car. Furthermore, to narrow means to go from wide to narrow, and conversely, to widen means to go from narrow to wide. 【0130】 Taking into account various dental positions and natural tooth shapes, the shape of the U-shaped cross section can vary along the length of the recess / recess wall. In the region of the upper and / or lower incisors, the U-shaped cross section can be, for example, V-shaped. 【0131】 Chapter 2 [Title of Invention] Dental Cleaning Device 【0132】 Chapter 2 of the present invention relates to a dental cleaning device, and more particularly to a dental cleaning device of the type that includes a mouthpiece having a recess, wherein the recess has a U-shaped cross-section and can have a predetermined curved length. 【0133】 [Background Technology for Chapter 2] Cleaning the teeth of humans and animals is essential for oral hygiene and internal health. Various dental cleaning devices are available, such as manual and electric toothbrushes. These typical toothbrushes recommend brushing your teeth in the prescribed manner for at least two minutes a day to effectively remove plaque. However, the average person does not spend the entire prescribed time cleaning their teeth, and / or does not always brush according to the effective method. 【0134】 People may apply excessive pressure to the tooth bristles while brushing their teeth, which not only causes the bristles to wear down rapidly and excessively, but also makes the brushing process ineffective, potentially damaging the teeth and causing gum recession, which can have detrimental effects on dental health. 【0135】 Therefore, there is a need for improved dental cleaning devices. More specifically, there is a need for dental cleaning devices that prevent brushing with excessive pressure. Furthermore, there is a need for dental cleaning devices that offer a greater degree of control over the brushing action, making ineffective brushing virtually impossible. 【0136】 Patent Document 1 discloses, in one embodiment, a physical stop for restricting the movement of a wall to which a bristle is attached. The stop prevents excessive pressure from being applied to the user's teeth. In another embodiment, Patent Document 1 discloses the use of an adjustable pressure setting valve. The valve releases pressure in the chamber when the maximum permissible pressure is exceeded. 【0137】 Patent Document 2 describes a system that uses a pair of valves to control the pressure inside a chamber. When the first valve is opened, an underpressure (partial vacuum) is generated beneath the membrane. When the second valve is opened, an overpressure is generated beneath the membrane. 【0138】 Patent Document 3 by the same applicant discloses an electronic valve configured to control the pressure inside a chamber of a dental cleaning device. This Patent Document 3 has not yet been published as of the priority date of this application. 【0139】 However, the need for more efficient and / or improved dental cleaning devices remains. [Prior art document] [Patent] 【0140】 [Patent Document 1] U.S. Patent No. 4,795,347 [Patent Document 2] International Publication No. 2010 / 076702 Pamphlet [Patent Document 3] International Application No. PCT / NL2018 / 050276 【0141】 [Summary of the inventions in Chapter 2] According to the first aspect of the present invention in Chapter 2, an improved dental cleaning device is provided, and the dental cleaning device is - A mouthpiece having a pressure chamber and a recess, wherein the recess has a U-shaped cross-section and is bounded by a flexible, deformable recess wall, and the pressure chamber is configured to contain a fluid under pressure; - A plurality of bristles, optionally, each attached to the recess wall by one end thereof and extending from the recess wall into the recess; - A pump unit, fluidly connected to the pressure chamber, configured to pump a predetermined volume of fluid into and out of the pressure chamber, thereby reciprocally increasing and decreasing the pressure inside the pressure chamber between an increased pressure state and a decreased pressure state, thereby deforming the recess wall, causing the recess wall to reciprocate and move, and increasing and decreasing the recess, respectively; - A pressure sensor configured to measure the pressure representing the pressure inside a pressure chamber, and also configured to produce a pressure signal representing the said pressure; - A controller configured to generate control signals; Includes; The pressure sensor and controller are connected so that the controller receives a pressure signal from the pressure sensor when in use, and the controller and pump unit are connected so that the pump unit receives a control signal from the controller when in use; The controller is configured to generate a control signal based on a pressure signal, and the pump unit is configured to deliver a predetermined amount into and / or out of the pressure chamber in response to the control signal; The controller is configured to reduce the amount of fluid delivered by the pump unit when the pressure in the pressure chamber exceeds a predetermined upper threshold. 【0142】 According to the present invention in Chapter 2, a dental cleaning device includes a pressure sensor and a controller. The pressure sensor is configured to measure a pressure representing the pressure in a pressure chamber. The pressure sensor may, for example, be located inside the pressure chamber, and the pressure sensor directly measures the pressure. Alternatively, the pressure sensor may be located in an inlet tube (for example, near the pressure chamber) located between the pump unit and the pressure chamber, and the pressure sensor measures the pressure of the fluid entering the pressure chamber. From the pressure, the pressure in the pressure chamber can be calculated and / or estimated. Further alternatively, the pressure sensor may be located in an inlet tube (for example, near the pump) located between the pump unit and the pressure chamber, and the pressure sensor measures the pressure of the fluid exiting the pump unit. From the pressure, the pressure in the pressure chamber can be calculated and / or estimated. Further alternatively, the pressure sensor may be integrated with the pump unit, and the pressure sensor measures the pressure of the fluid exiting the pump unit. From the pressure, the pressure in the pressure chamber can be calculated and / or estimated. 【0143】 While measuring the pressure inside a pressure chamber, the pressure may be compared to a reference pressure (e.g., ambient pressure). Then, a relative pressure may be measured, and the measured pressure is relative to the reference pressure (ambient pressure). Alternatively, an absolute pressure measurement may be performed, measuring the absolute value of the pressure inside the pressure chamber. 【0144】 According to the present invention in Chapter 2, a pressure sensor and a controller are connected. That is, the pressure sensor and the controller are arranged to communicate with each other, and signals can be sent from the pressure sensor to the controller (and / or vice versa). The connection can be, for example, a wired connection or a wireless connection. The pressure sensor produces a pressure signal representing the pressure (in the pressure chamber) measured by the pressure sensor. This pressure signal is sent to the controller when the dental cleaning device is in use, and the controller receives the signal. 【0145】 According to the present invention in Chapter 2, the controller is configured to generate a control signal based on a pressure signal. For example, the control signal can indicate whether the pressure in the pressure chamber is too high, within a predetermined boundary, or too low. The control signal can be generated continuously. For example, when the pressure signal indicates that the pressure in the pressure chamber is too high (when the pressure exceeds a preset upper threshold), the control signal can change from the control signal generated when the pressure in the pressure chamber is within a predetermined boundary. Thus, a change in the control signal can indicate that the dental cleaning device is not functioning as desired. When the pressure signal indicates that the pressure in the pressure chamber is below a preset upper threshold, the control signal can have other characteristics. For example, the control signal generated when the pressure is below a preset upper threshold can indicate to the pump unit that the dental cleaning device is functioning as desired. 【0146】 Alternatively, the control signal can be a switch-type signal, which is generated only when the pressure exceeds a predetermined threshold, or only when the pressure is within a desired boundary. Therefore, the control signal may not be generated continuously. 【0147】 According to the present invention in Chapter 2, the controller and the pump unit are connected. That is, the controller and the pump unit are arranged to communicate with each other, and signals can be sent from the controller to the pump unit (and / or vice versa). The connection can be, for example, a wired connection or a wireless connection. When the controller generates a control signal, the signal is sent to the pump unit when the dental cleaning device is in use, and the pump unit receives the signal. In response to the control signal, the pump unit delivers a predetermined amount into and / or out of the pressure chamber. 【0148】 Therefore, when performing its job, the pump unit delivers fluid into and out of the pressure chamber at a delivery rate between, for example, 0 liters per minute and 4 liters per minute. The pump unit may be configured to deliver a preset fluid delivery rate (liters per minute) into and out of the pressure chamber. Then, upon receiving a control signal, the pump unit can either continue its work at the current delivery rate, decrease the delivery rate, or increase the delivery rate, respectively. If the pressure measured in the pressure chamber is too low, the delivery rate may be increased. Generating a control signal based on a pressure signal makes it possible to ensure that the pressure is maintained below a predetermined upper threshold. Alternatively, the control signal may change when the upper threshold is reached, indicating that the delivery rate of the pump unit should be changed. 【0149】 According to the present invention in Chapter 2, the controller of a dental cleaning device is configured to reduce the amount of air delivered when a predetermined upper threshold is exceeded. That is, the controller may be configured to reduce the amount of air pumped into the pressure chamber by the pump unit when the pressure in the pressure chamber exceeds an upper threshold. As a result of reducing the amount of air delivered by the pump, the pressure in the pressure chamber decreases, preventing the user from brushing their teeth or gums with excessive pressure while the dental cleaning device operates more efficiently (for example, with less power consumption, which can result in less frequent battery recharging), thus improving its operation. 【0150】 Furthermore, by controlling the amount of fluid delivered by the pump via a control signal based on pressure measurement, excessive pressure during tooth brushing is prevented. 【0151】 The dental cleaning device according to the present invention in Chapter 2 includes a mouthpiece having at least one recess, which can be, for example, one or two recesses. This at least one recess has a U-shaped cross-section. The mouthpiece includes a recess wall for each recess that defines the boundary of each recess. The recess wall can be flexible and / or deformable. The recess wall can be formed from a sheet, which can be made from, for example, a thermoplastic elastomer, a silicone elastomer, or a silicone polymer. The recess wall is optionally lined with a plurality of bristles, each having one end attached to the recess wall and extending from the recess wall into the recess. In other words, the mouthpiece has a recess, and the recess wall of the recess can be covered by bristles distributed across the wall of the recess. At least one dental location (such as a tooth element at this location, or the gums covering the jawbone at the location of that dental location) can be received in the recess, and if present, the bristle in the recess will be able to brush at least one dental location on both the lingual (facing the user's tongue) and faculties (facing the user's lips / cheeks), and preferably, on the free end surface of the tooth (the masticatory surface / edge facing the opposite jawbone). Alternatively, the bristle in use (if present) faces the user's teeth. The bristle may be made from nylon, elastomer, or any other suitable material. In cases of toothless dental arches, the remaining gingival arch may also require treatment. In these cases, the gums can be massaged by the recessed walls, with or without bristles. For improved gum cleaning, a cleaning fluid may be used in such mouthpieces without bristles. 【0152】 The mouthpiece according to the present invention of Chapter 2 has at least one pressure chamber configured to contain a fluid under pressure, the pressure of which can be increased and decreased. The main body is configured to deform a recessed wall by reciprocating (alternating) increasing and decreasing the pressure in at least one pressure chamber, causing a sustained, repeated reciprocating motion of the recessed wall and (if present) a bristle on the recessed wall. The mouthpiece may include one, two, three, four, five, six, or any other number of pressure chambers that can be filled with fluid, as described in Patent Document 3, which is under the name of the same applicant and has not yet been published as of the priority date of this application. By alternately (reciprocating) increasing the pressure in at least one of the pressure chambers from a reduced pressure state to an increased pressure state, and decreasing the pressure in this pressure chamber from an increased pressure state to a reduced pressure state, and by continuously repeating this reciprocating motion, the recessed wall bearing an optional bristle is moved, resulting in the recessed wall and the bristle acting on an object (teeth and / or gums present in these dental locations) at the dental location to clean the object. 【0153】 The recess is bounded by a recess wall. For example, a flexible, deformable recess wall that can similarly define the boundary of a portion of a pressure chamber can also be the wall of the pressure chamber. Alternatively, however, the recess wall can also be formed by one or more rigid pressure plates. 【0154】 Regarding the technical terms "increased pressure state" and "decreased pressure state," it should be noted that these states are related to each other; that is, in a decreased pressure state, the pressure is reduced (to a lower level) than in an increased pressure state, and vice versa. In both states, the pressure can be lower than the ambient pressure. 【0155】 The length of the mouthpiece (measured transversely to the U-shaped cross-section along the user's dental arch) can be approximately equal to the width of a human or animal tooth. The user of the dental cleaning device can then move it along the dental arch to be brushed (for example, first along the mandibular arch and then along the maxillary arch, or vice versa). Alternatively, the length of the mouthpiece can be the length of at least five teeth, so that at least five dental positions can be brushed simultaneously. For example, the length of the mouthpiece (measured transversely to the U-shaped cross-section along the user's dental arch) can be measured as follows: - A length extending at least equal to the distance from the second premolar on the left side to the second premolar on the right side of the dental arch of a human (for example, an adult); - A length extending at least equal to the distance from the left first molar to the right first molar in the dental arch of a human (e.g., an adult); or, - A length that extends substantially the entire length of the user's dental arch (i.e., the arch from at least the left second molar to the right second molar) so that the entire dental arch can be brushed simultaneously. 【0156】 Furthermore, the length axis of the arch shape can have a shape similar to that of the human dental arch, or at least a shape similar to that of a part of the human dental arch. 【0157】 The dental cleaning device according to the present invention in Chapter 2 further includes a pump unit disposed in fluid communication with the pressure chamber, the pump unit being configured to reciprocately increase and decrease the pressure in the pressure chamber between an increased pressure state and a decreased pressure state by pumping a predetermined volume of fluid into and out of the pressure chamber, respectively, thereby deforming the recess walls, moving the recess walls reciprocally, and increasing and decreasing the recesses, respectively. Thus, the pump unit has a pumping action, which continuously increases and decreases the pressure in the pressure chamber. For example, the pump unit includes a pumping device configured to pump fluid into the pressure chamber and a suction device configured to suck fluid out of the pressure chamber, and is capable of alternately increasing and decreasing the pressure in the pressure chamber between the increased pressure state and the decreased pressure state. By moving the recess walls reciprocally and alternately, and increasing and decreasing the recesses, respectively, the user's teeth and / or gums are brushed, improving the user's oral hygiene. 【0158】 In a further embodiment of the first aspect of the present invention in Chapter 2, the pump may be configured to operate at a predetermined operating frequency (for example, within a narrow frequency range around this predetermined operating frequency). Alternatively, the controller may be configured to operate the pump at a predetermined operating frequency (for example, within a narrow frequency range around this predetermined operating frequency). Furthermore, alternatively or additionally, the controller may be configured to reduce the delivery amount of the pump unit when the pressure in the pressure chamber exceeds a predetermined upper threshold, thereby preventing changes in the operating frequency. 【0159】 Depending on design parameters such as bristle length, bristle stiffness, and the characteristics of the flexible, deformable recessed wall, the brushing / cleaning action of a dental cleaning device can be optimized at a specific operating frequency. Preferably, the dental cleaning device operates at that operating frequency when the device is being used and after a control signal indicates that the upper pressure threshold has been reached (the reciprocal increase and decrease of the pressure in the pressure chamber occurs at that operating frequency). For example, if the fluid in the pressure chamber is a gas, the reciprocal increase and decrease of the pressure in the pressure chamber may be ineffective in moving the recessed wall at higher frequencies and may be uncomfortable for the user. This is also true if the fluid is a liquid. Furthermore, if a flexible, deformable recessed wall is used, the recessed wall may not deform in response to the reciprocal increase and decrease of the pressure in the pressure chamber at higher frequencies. 【0160】 Therefore, when changing the operation of the dental cleaning device after the indication, the operating frequency (the pump unit operates at or is operated at that operating frequency) is not changed according to this further embodiment so that the pump operates at a predetermined operating frequency. 【0161】 The predetermined operating frequency can be a fixed value, for example, 8 Hz. According to the present invention in Chapter 2, the intention may be to control the pump delivery amount without affecting the pump's operating frequency, but as a side effect of the control action, ripple may occur within the operating frequency, for example, at a fixed predetermined operating frequency of 8 Hz, ripple may occur in the range of ±0.5 Hz to ±1 Hz. 【0162】 Furthermore, the predetermined operating frequency can vary as a function of time. In other words, the pump unit can have an operating frequency that varies according to a predetermined function of time measured after the pump is switched on. In the equation, this can be read as ft = x(t). Each time the pump is switched on, the predetermined function starts again at t=0. x(t) is a predetermined continuous or discontinuous function of time. For example, the operating frequency can start at a low frequency at t=0, then increase to a higher frequency, and finally decelerate to a lower frequency (e.g., after 20-30 seconds). Starting at a low frequency can prevent the user from being startled when the pump is switched on, and ending at a low frequency can indicate to the user that brushing is almost complete, while being in the range of frequencies may be optimal for good brushing results. Furthermore, it should be noted that, according to the present invention in Chapter 2, while the intention may be to control the pump delivery amount without affecting the pump's operating frequency, a side effect of the control action may be the occurrence of ripple within the operating frequency, for example, ripple in the range of ±0.5 Hz to ±1 Hz. 【0163】 The predetermined operating frequency can be in the range of 0.5 Hz to 20 Hz, both in the case of a fixed operating frequency and in the case of an operating frequency that changes over time. 【0164】 In another further embodiment of the first aspect of the present invention in Chapter 2, the upper threshold is at most 2 bar relative to ambient pressure, for example, at most 1 bar relative to ambient pressure. Excessively high pressure in the pressure chamber can result in an unpleasant user experience for the user of the dental cleaning device and can easily result in excessive brushing force. In addition, excessively high pressure can cause rupture of the recess walls, which may, in some cases, result in harm to the user and / or economic loss of the dental cleaning device. The above upper threshold of at most 2 bar relative to ambient pressure may be low enough to eliminate these adverse effects. Preferably, the upper threshold is at most 0.3 bar relative to ambient pressure (1.3 times the ambient pressure), for example, at most 0.2 bar relative to ambient pressure (1.2 times the ambient pressure). At such pressures, the brushing action of the dental cleaning device is still sufficient, while reducing the risk of damaging the user's gums and the other adverse effects described. 【0165】 It should be noted that direct pressure measurement (where absolute pressure is measured) may be difficult to achieve in the dental cleaning device according to the present invention as described in Chapter 2. Instead of measuring absolute pressure, it is foreseeable that a comparison with a reference pressure (e.g., ambient pressure) will be performed to determine the pressure inside the pressure chamber. Thus, for example, the expression "0.3 bar relative to ambient pressure" could alternatively mean "approximately 1.3 times the ambient pressure" or "a pressure of approximately 1.3 bar," depending on the specific measurement performed. Ambient pressure is generally known to be approximately 1 bar everywhere on Earth, depending, for example, on geographical location, altitude, and weather conditions. 【0166】 In yet another further embodiment of the first aspect of the present invention in Chapter 2, the controller may be further configured to increase the delivery volume of the pump unit when the pressure in the pressure chamber falls below a predetermined lower threshold, for example, in increased pressure conditions and / or decreased pressure conditions. As with situations where the pressure in the pressure chamber is too high, too low a pressure can also adversely affect the operation of the dental cleaning device. For example, when the pressure is too low, the bristle of the dental cleaning device may not be able to rub against the user's teeth with sufficient force, resulting in inadequate cleaning / brushing of the teeth. Therefore, according to this yet another further embodiment, the delivery volume (and thus the pressure in the pressure chamber as well) is increased when the pressure in the pressure chamber falls below the lower threshold. 【0167】 In the details of this further embodiment, the lower threshold value can be less than or equal to 1 bar less than or equal to the upper threshold value. That is, the maximum pressure difference in the pressure chamber (allowable by the controller) can be less than or equal to 1 bar. For example, when the upper threshold is 1.3 bar (ambient pressure plus 0.3 bar), the lower threshold can be 0.3 bar (ambient pressure minus 0.7 bar). For example, the difference between the upper threshold value and the lower threshold value can be 0.4 bar. However, the nominal pressure difference between the decreased pressure state and the increased pressure state can be less than or substantially less than the difference between the upper threshold value and the lower threshold value. That is, the upper and lower thresholds may not be reached in every pressurization cycle. For example, when the difference between the upper threshold value and the lower threshold value is 0.4 bar, the nominal pressure difference between the increased pressure state and the decreased pressure state can be as little as 0.1 bar or 0.2 bar. 【0168】 In another detail of this further embodiment, the lower threshold can be in the range of -0.5 bar to +0.2 bar (0.5 to 1.2 times the ambient pressure) relative to the ambient pressure, for example, in the range of -0.5 bar to 0 bar (0.5 to 1 time the ambient pressure). Thus, the pressure inside the pressure chamber can be below the ambient pressure in a reduced pressure state, and conversely, the pressure inside the pressure chamber can be above the ambient pressure in a reduced pressure state. 【0169】 According to a second aspect of the present invention in Chapter 2, a dental cleaning device is provided for brushing multiple dental positions simultaneously, and the dental cleaning device is - A mouthpiece having a pressure chamber and a recess, wherein the recess is bounded by a recess wall, the recess wall is flexible and deformable, the recess has a curved longitudinal and transverse U-shaped cross-section, the recess is configured to encompass a portion of the user's dental arch extending from at least the left second premolar to at least the right second premolar when viewed in the curved longitudinal direction, and the pressure chamber is configured to contain a fluid under pressure; - Optionally, a plurality of bristles, each having one end attached to the recess wall and extending into the recess away from the recess wall; - A pump unit is arranged in fluid communication with the pressure chamber, and is configured to reciprocately increase and decrease the pressure inside the pressure chamber between an increased pressure state and a decreased pressure state by pumping a predetermined volume of fluid into and out of the pressure chamber, thereby deforming the recessed wall, moving the recessed wall back and forth, and increasing and decreasing the recess, respectively. The pump unit operates at a predetermined operating frequency during operation. Includes, The operating frequency ranges from 0.5Hz to 20Hz. 【0170】 The mouthpiece of the dental cleaning device according to the second aspect of the present invention in Chapter 2 is similar to the mouthpiece of the dental cleaning device according to the first aspect of the present invention in Chapter 2. In addition, the recess of the mouthpiece has a curved longitudinal direction and is configured to encompass a substantial portion of the user's dental arch (e.g., substantially the entire dental arch) when viewed in the curved longitudinal direction. For example, the recess may be configured to encompass dental positions ranging from at least the left first molar to at least the right first molar, or to encompass dental positions ranging from at least the left second molar to at least the right second molar. Then, all or almost all of the user's teeth in the dental arch can be brushed simultaneously by the dental cleaning device. 【0171】 The dental cleaning device according to the second aspect of the present invention in Chapter 2 optionally has a plurality of bristles similar to those of the dental cleaning device according to the first aspect of the present invention in Chapter 2. 【0172】 The dental cleaning device according to the second aspect of the present invention in Chapter 2 includes a pump unit similar to that of the dental cleaning device according to the first aspect of the present invention in Chapter 2. 【0173】 According to a second aspect of the present invention in Chapter 2, the pump unit operates at an operating frequency in the range of 0.5 Hz to 20 Hz. 【0174】 In contrast to known dental cleaning devices (which operate at fairly high frequencies), the dental cleaning device according to the second aspect of the present invention in Chapter 2 operates at a relatively low frequency (compared to devices from the prior art). For example, the dental cleaning device of Patent Document 2 operates at a frequency between 100 Hz and 300 Hz. This high-frequency movement allows the bristle (which, in Patent Document 2, is made from nylon and attached to a membrane) to function as a jackhammer, and this jackhammer functionality is necessary to remove plaque from the teeth of the user of the dental cleaning device. However, moving the bristle by such high frequencies presents difficulties. Indeed, Patent Document 2 refers to the inertia of the total fluid volume and the difficulty of overcoming the cavitation effect in the fluid generated by the pumping action. Patent Document 2 teaches how to solve these problems. With respect to dental cleaning devices that operate like a jackhammer, it is generally known that high frequencies are required (despite these known difficulties). The reason is that otherwise, teeth cleaning would take too long, and the user of the dental cleaning device would not be able to clean their teeth sufficiently. 【0175】 The dental cleaning device according to the second aspect of the present invention in Chapter 2 takes a fundamentally different approach compared to Patent Document 2. Instead of finding a suitable method for moving the bristle at a very high frequency, the dental cleaning device according to the present invention in Chapter 2 brushes the teeth at a considerably lower operating frequency of 0.5 Hz to 20 Hz. Reciprocating the pressure in the pressure chamber at a lower operating frequency than at a higher operating frequency is far more energy efficient. The dental cleaning device according to the second aspect of the present invention in Chapter 2 provides a mouthpiece including a recess, which is configured to encompass substantially the entire dental arch of the user and has a U-shaped cross-section, so that (almost) all teeth, and all sides of each tooth, can be brushed simultaneously by the dental cleaning device according to the second aspect of the present invention in Chapter 2. When operating the bristle at a lower frequency, instead of acting as a jackhammer, the bristle can act as a windscreen wiper, so to speak, rubbing against the user's teeth as it moves toward them, removing plaque by its rubbing action. The aforementioned rubbing action can only be effectively performed at relatively low frequencies in the range of 0.5 Hz to 20 Hz. When the bristle's moving frequency is too high, a jackhammer (chipping) action occurs instead of a rubbing action, requiring frequencies much higher than 20 Hz. When the moving frequency is lower than 0.5 Hz, the movement is too slow, and while rubbing can be performed satisfactorily, the total brushing time increases excessively. 【0176】 The dental cleaning device according to the second aspect of the present invention in Chapter 2 results in highly efficient alternating movement of the recess walls and bristle, while the dental arch can still be cleaned in a satisfactory amount of time by simultaneously rubbing the teeth and removing plaque at substantially all dental positions of the dental arch. 【0177】 By operating at a relatively low operating frequency and simultaneously brushing virtually all teeth in the user's dental arch by rubbing the teeth, the proposed dental cleaning device makes incorrect use and ineffective brushing of the teeth virtually impossible. 【0178】 Additionally, brushing teeth with a relatively low operating frequency can result in a more comfortable feeling in the mouth when using dental cleaning devices. 【0179】 In a further embodiment of the second aspect of the invention in Chapter 2, the operating frequency is in the range of 1 Hz to 15 Hz, for example, in the range of 3 Hz to 10 Hz. These operating frequency ranges provide an optimal trade-off between the desired brushing time and the brushing result achieved. 【0180】 In another further embodiment of the second aspect of the invention in Chapter 2, the operating frequency can be a predetermined frequency, which is fixed or varies as a function of time. As described in relation to the first aspect of the invention in Chapter 2, this predetermined frequency can be maintained, for example, when responding to pressure changes, due to the pump being configured to operate at a predetermined operating frequency, or due to the controller being configured to operate the pump at a predetermined operating frequency. 【0181】 In further embodiments of the first and / or second aspects of the present invention as described in Chapter 2, the recess wall is fabricated from a material having a hardness of 20 Shore A to 100 Shore A as measured according to ISO 7619-1:2010. For example, the recess wall may be fabricated from an elastomer, such as a thermoplastic elastomer or silicone elastomer. Materials having a hardness of 20 Shore A to 100 Shore A, for example, 50 Shore A to 80 Shore A, can provide an optimal trade-off between flexibility, deformability, rigidity, and durability during continuously repeated deformation. 【0182】 In the details of this further embodiment, at least some of the multiple bristle may be made from a material having a hardness from 20 Shore A to 100 Shore A. For example, the bristle may be made from an elastomer, such as a thermoplastic elastomer or silicone elastomer, or from a silicone polymer. This range makes it possible to provide the bristle with an optimal trade-off between rigidity, flexibility, and deformability. On the one hand, it is desirable for the bristle to be relatively hard in order to increase its durability and to rub the teeth with enough force to actually clean them. On the other hand, it is desirable for the bristle to be easily deformable in order to rub and clean the teeth of the user of the dental cleaning device (instead of damaging the teeth) and to reach spots that are difficult to reach with harder bristle. 【0183】 In another embodiment of the first and / or second aspect of the invention of Chapter 2, the recess wall is made of a material having a hardness of 50 Shore D to 100 Shore A as measured according to ISO7619-1:2010. For example, the recess wall can be made of a thin plastic, such as polyethylene, polybutylene terephthalate, polypropylene, polyester, or nylon. Materials having a hardness of 50 Shore D to 100 Shore D, for example, 70 Shore D to 90 Shore D (used in thin recess walls), can provide an optimal trade-off between flexibility, deformability, rigidity, and durability during continuously repeated deformations. 【0184】 In the details of this further embodiment, at least some of the plurality of bristles can be made of a material having a hardness of 50 Shore D to 100 Shore D. For example, the bristles can be made of a plastic, such as polyethylene, polybutylene terephthalate, polypropylene, polyester, or nylon. This range can provide an optimal trade-off for the bristles among thinner bristles with appropriate rigidity, flexibility, and deformability. On the one hand, in order to enhance the durability of the bristles and to rub the teeth with a force sufficient to actually clean the teeth, the bristles are preferably relatively hard. On the other hand, in order to rub the teeth of the user of the dental cleaning device to clean the teeth (instead of damaging the teeth) and to reach spots that are difficult to reach with harder bristles, it is desirable that the bristles deform easily. 【0185】 In another detail of this further embodiment, the bristles and the recess walls are made of the same material. Alternatively, the bristles can be made from a nylon material having a hardness significantly higher than 70 Shore D, while the recess walls are made from, for example, a thermoplastic elastomer or a silicone elastomer having a hardness in the range of 40 Shore A to 100 Shore A. 【0186】 In another further embodiment of the first and / or second aspect of the present invention of Chapter 2, the mouthpiece of the dental cleaning device has two of the said recesses, the two recesses each having a U-shaped cross-section and being bounded by the recess walls, and the openings of the U-shaped cross-sections of the two recesses facing in opposite directions. This enables simultaneous brushing of the teeth and / or gums of the lower dental arch and the upper dental arch. 【0187】 In another further embodiment of the first and / or second aspect of the present invention of Chapter 2, one or two of the recesses have an elongated curved shape and are configured to encompass at least five dental positions of the user, such as dental positions in the range from the left first molar to the right first molar. This advantageously enables simultaneous brushing of a plurality of dental positions. Then, satisfactory tooth brushing can be achieved in less time compared to a dental cleaning device having shorter recesses. The recess can be configured to encompass dental positions in the range from the left second molar to the right second molar. The mouthpiece can extend over substantially the entire dental arch of the user, including or excluding the third molar (wisdom tooth). 【0188】 In another further embodiment of the first and / or second aspects of the present invention as described in Chapter 2, when the pressure in the pressure chamber is increased during the use of the dental cleaning device, the bristle of the dental cleaning device moves toward the user's dental position with the end portion of the bristle deformed (bent) and rubbing against the teeth, and this rubbing action of the end portion cleans the teeth. Thus, in contrast to known automatic dental cleaning devices, the dental cleaning device according to the present invention as described in Chapter 2 does not function as a jackhammer, but instead rubs the teeth by using friction between the bristle and the teeth as a cleaning mechanism for removing plaque from the user's teeth. 【0189】 In certain embodiments of the first and / or second aspects of the present invention as described in Chapter 2, the fluid can be a gas, preferably air. Air is readily available and can be extracted from the environment, for example, while the dental cleaning device is operating. Using a different fluid may require the use of a closed-loop fluid system, which may be more expensive and cumbersome to produce. When using air as the fluid, an open-loop or partially open-loop system may be used, where the fluid is allowed to exit, for example, from a pressure chamber to the outside of the dental cleaning device. 【0190】 In one embodiment of a second aspect of the present invention as described in Chapter 2, the dental cleaning device further includes a pressure sensor configured to measure a pressure representing the pressure in a pressure chamber and to produce a pressure signal representing the measured pressure, and a controller configured to generate a control signal; the pressure sensor and the controller are connected so that the controller receives the pressure signal when in use, and the controller and a pump unit are connected so that the pump unit receives the control signal when in use; the controller is configured to generate a control signal based on the pressure signal, and the pump unit is configured to provide a predetermined delivery amount reciprocally into and / or out of the pressure chamber in response to the control signal; the controller is configured to reduce the delivery amount of the pump unit when the pressure in the pressure chamber exceeds a predetermined upper threshold, as described according to a first aspect of the present invention as described in Chapter 2. 【0191】 In some embodiments of the first and / or second aspects of the present invention as described in Chapter 2, the recessed wall may have an internal width between the legs of the U-shaped cross-section in the range of 2 mm to 10 mm, for example, 3 mm to 7 mm, when viewed in the plane of the U-shaped cross-section transverse to the length axis; and / or the U-shape may have an internal height in the range of 5 mm to 15 mm, for example, 5 mm to 10 mm. These measurements are given with respect to adults. With respect to children or animals, these measurements may differ. 【0192】 According to a third aspect of the present invention in Chapter 2, a method for operating a dental cleaning device for simultaneously brushing multiple dental positions, wherein the cleaning device is - A mouthpiece having a pressure chamber and a recess, wherein the recess is bounded by a recess wall, has a U-shaped cross-section in a curved longitudinal direction and transversely to the longitudinal direction, is configured to encompass at least a portion of the user's dental arch when viewed in the curved longitudinal direction, and the pressure chamber is configured to contain a fluid under pressure; - Optionally, a plurality of bristles, each having one end attached to the recess wall and extending into the recess away from the recess wall; - A pump unit is arranged in fluid communication with the pressure chamber, and is configured to pump a predetermined volume of fluid into and out of the pressure chamber, thereby reciprocatingly increasing and decreasing the pressure inside the pressure chamber between an increased pressure state and a decreased pressure state, thereby deforming the recessed wall, moving the recessed wall back and forth, and increasing and decreasing the recess, respectively. Includes, - When the pressure in the pressure chamber exceeds a predetermined upper threshold, the delivery volume of the pump unit is reduced; and / or, - A method is provided in which the pump unit operates at an operating frequency in the range of 0.5 Hz to 20 Hz. 【0193】 According to the third aspect of the present invention in Chapter 2, - When the pressure in the pressure chamber exceeds a predetermined upper threshold, the pump may be operated in such a manner that changes in the operating frequency are prevented; and / or, - The pump may operate at a fixed operating frequency; and / or, - The pump may operate at an operating frequency in the range of 1Hz to 15Hz, for example, in the range of 3Hz to 10Hz; and / or, - The upper threshold can be at most 2 bar relative to the ambient pressure, for example, at most 1 bar; and / or, - The upper threshold can be at most 0.3 bar relative to the ambient pressure, for example, at most 0.2 bar; and / or, - The delivery volume of the pump unit may be increased when the pressure in the pressure chamber drops below a predetermined lower threshold: The lower threshold can be below the upper threshold, in a range of up to 1 bar, for example, up to 0.4 bar; and / or, ○ The lower threshold can be in the range of -0.5 bar to +0.2 bar relative to the ambient pressure, for example, in the range of -0.5 bar to 0 bar; and / or, - The pump operates at an operating frequency that changes according to a predetermined function of the time measured after the pump is switched on. 【0194】 [Brief explanation of the drawings in Chapter 2] The present invention as described in Chapter 2 will be further explained with reference to Figures 21 to 26. 【0195】 [Figure 21] This is a schematic diagram showing a portion of the human dental arch. [Figure 22] This figure schematically shows an embodiment of the mouthpiece of the dental cleaning device according to the present invention as described in Chapter 2. [Figure 23a] This figure schematically shows a cross-section of the mouthpiece in Figure 22 under the reduced pressure conditions. [Figure 23b] This figure schematically shows a cross-section of the mouthpiece in Figure 22 under the increased pressure conditions. [Figure 24] This figure schematically shows an embodiment of the dental cleaning device according to the present invention as described in Chapter 2. [Figure 25] This figure schematically shows a graph of the pressure inside the pressure chamber as a function of time. [Figure 26] This figure schematically shows tooth rubbing by the bristle of a dental cleaning device according to an embodiment of the present invention in Chapter 2. 【0196】 [Detailed explanation of the diagram in Chapter 2] Figure 21 very schematically shows in perspective a part of the upper dental arch or maxillary dental arch 301 with dental positions 302 to 314. Each dental position is indicated by a vertical dashed line. Each dental position typically includes teeth named according to a nomenclature known to each dentist. Using this nomenclature: - Dental position 302 is the position of the left "second molar" shown in Figure 21; - Dental position 303 is the position of the left "first molar" which is missing in Figure 21; - Dental position 304 is the position of the left "second premolar" shown in Figure 21; - Dental position 305 is the position of the left "first premolar" shown in Figure 21; - Dental position 306 is the position of the left "canine" shown in Figure 21; - Dental position 307 is the position of the left "lateral incisor" which is missing in Figure 21; - Dental position 308 is the position of the left "central incisor" shown in Figure 21; - Dental position 309 is the position of the right "central incisor" shown in Figure 21; - Dental position 310 is the position of the right "lateral incisor" shown in Figure 21; - Dental position 311 is the position of the right "canine" shown in Figure 21; - Dental position 312 is the position of the right "first premolar" shown in Figure 21; - Dental position 313 is the position of the right "second premolar" shown in Figure 21; - Dental position 314 is the position of the right "first molar" shown in Figure 21. 【0197】 In Figure 21, the dental position of the right "second molar" is not shown, nor are the dental positions of the right and left "third molars" (also called wisdom teeth). Similarly, the lower (mandibular) dental arch (jaw) has a similar number of dental positions, which are named similarly according to the said nomenclature. 【0198】 Figure 21 further illustrates a system of three mutually orthogonal axes, including the x-axis X, y-axis Y, and z-axis Z. The z-axis Z is a curved axis following the contour of the dental arch 301. The x-axis X and y-axis Y are perpendicular to each other and define the xy-plane, which is essentially flat and perpendicular to the dental arch 301; that is, each xy-plane intersecting at a given point on the z-axis is perpendicular to the curved z-axis Z at that point. The z-axis Z defines the curved longitudinal direction. The z-axis Z and y-axis Y define the curved zy-plane, which, when viewed along the z-axis, has an arc shape similar to the shape of the dental arch. Furthermore, the z-axis Z and x-axis X define the zx-plane. 【0199】 Figure 22 schematically shows a perspective view of an example of a mouthpiece 320 or dental cleaning device according to the first and / or second aspects of the present invention of Chapter 2. Figures 23a and 23b show cross-sections of the mouthpiece of Figure 22 as seen by arrow XXIII in Figure 22. In the cross-section of Figure 23a, the pressure chamber is in a relatively reduced pressure state, while in Figure 23b, the pressure chamber is in a relatively increased pressure state. 【0200】 The mouthpiece 320 includes a first recess 322. This first recess 322 has a curved longitudinal direction when viewed along the z-axis in Figure 21, and has a U-shaped cross-section when viewed in the xy-plane of Figure 21. The first recess 322 is bounded by a flexible and / or deformable recess wall 323, which is U-shaped in the xy-plane. The recess wall 323 is lined by a plurality of bristle 324, each having one end (called a root portion 319) attached to the flexible recess wall 323 and extending into the first recess 322. 【0201】 Here, the recess 322 has an elongated, curved shape and is configured to substantially encompass the entire dental arch of the user. With respect to the dental cleaning device according to the first aspect of the present invention in Chapter 2, the recess 322 can be much shorter and extend, for example, to only a single dental location or to at least five dental locations (for example, from the first molar on the left side of the jaw to the first molar on the right side of the jaw). 【0202】 Reference numeral 326 indicates a nipple, which is configured to connect the mouthpiece to the pumping and / or suction device, as will be described in more detail below with reference to Figure 24. The mouthpiece 320 further has a right half 327 and a left half 328, which these halves come together in what is called the nipple 326. 【0203】 Reference numeral 325 indicates a curved dividing line, which defines a mirror plane parallel to the xz plane as defined in Figure 21. The mouthpiece shown in Figure 22 is, so to speak, mirror symmetric with respect to this mirror plane, meaning that a second recess (not visible in Figure 22, but visible in Figures 23a and 23b) exists opposite the first recess 322, and this second recess is also lined with bristle. It should be noted that since the upper and lower arches (teeth) of the dental position generally have different shapes, the first recess can have a different shape from the second recess. 【0204】 The recess 322 is configured to encompass substantially the entire dental arch, for example, from the dental position of the right third or second molar to the dental position of the left third or second molar, respectively. With regard to the first aspect of the present invention in Chapter 2, the recess 322 may also be configured to encompass a portion of the arch of dental positions, which portion includes, for example, only a single dental position. 【0205】 Figures 23a and 23b show cross-sections of the right-hand component of the mouthpiece 320 indicated by arrow XXIII in Figure 22. The pressure inside the pressure chamber is increased in Figure 23b (compared to the situation in Figure 23a), and the pressure inside the pressure chamber is decreased in the situation in Figure 23a (compared to the situation in Figure 23b). 【0206】 As best seen in Figures 23a and 23b, the bristle may be provided as a tuft 329 of a relatively thin bristle 324. Each tuft 329 may have a base 336, the bases 336 supporting the bristle 324 at their roots 319 and attached to a flexible recess wall 323. 【0207】 As can be seen in Figures 23a and 23b, the mouthpiece 320 has a first recess 322 on its upper side and a second recess 322 on its lower side, with the upper and lower recesses 322 facing opposite directions relative to each other. Both recesses 322 are bounded by a flexible recess wall 323. In a cross-section parallel to the xy-plane as defined in Figure 21, the recess wall 323 is U-shaped and has a recess wall base 334 and two recess wall legs 333, the two recess wall legs 333 extending from the recess base wall. The recess wall 323 is covered by a bristle tuft 329 over the recess wall legs 333 and / or base 334. 【0208】 Inside the mouthpiece is a pressure chamber 335, which can be filled with a fluid via a nipple 326 (Figure 22). The fluid can be a gas, such as air, or a liquid, such as water. In an embodiment as shown in Figure 22, the mouthpiece has one pressure chamber. However, it should be noted that the mouthpiece can contain multiple pressure chambers, such as five pressure chambers, or any other number of pressure chambers. Unpublished Patent Document 3 shows examples of other numbers of pressure chambers in Figures 4, 5, 7, 9, and 10. In the case of multiple pressure chambers, all pressure chambers or groups of pressure chambers can be fluidly connected to each other, as described in Unpublished Patent Document 3 according to the present invention in Chapter 2. 【0209】 As can be seen in Figures 23a and 23b, the mouthpiece may include an internal support structure made of a rigid material relative to the material of the flexible recessed wall 323. This support structure may include a lingual plate 330 and a facial plate 332, both of which extend along a curved zy-plane as defined in Figure 21, and consequently have a U-shape when viewed along the z-axis. To maintain the lingual plate 330 and the facial plate 332 at a predetermined distance from each other, the support structure may include one or more spacers 331. These one or more spacers 331 may be, for example, multiple bars or wires or a single plate, which may extend essentially parallel to the zx-plane as defined in Figure 21. In the case of a single plate as a spacer, this plate may divide the pressure chamber 335 into two pressure chambers (an upper chamber and a lower chamber). These two pressure chambers may be in fluid communication with each other through one or more through-holes through the plate. In the case of large through-holes and / or multiple through-holes, the two pressure chambers may effectively be a single pressure chamber. 【0210】 The mouthpiece shown in Figure 22 is configured to brush multiple dental locations simultaneously. If teeth are present, each dental location will be brushed. The remaining portion of a dental location, such as the gums, may be brushed if teeth are missing, and teeth adjacent to the missing tooth location may be additionally brushed by bristle designed for the missing tooth location. 【0211】 A single pressure chamber 335 includes a first flexible recess wall 323 defining the boundary of a first recess 322 (the upper one in Figures 23a and 23b) and a second flexible recess wall 323 defining the boundary of a second recess 322 (the lower one in Figures 23a and 23b). The first and second recess walls 323 are deformable, in particular, by increasing or decreasing the pressure in the pressure chamber 335. The flexible recess walls 323 may be made from an elastic material, such as a rubber-like material. Alternatively, the flexible recess walls 323 may be made from an inelastic material. When there is virtually no or low pressure difference across the inner and outer sides of the flexible recess wall 323 (when the pressure in the pressure chamber is substantially equal to the ambient pressure), the material of the flexible recess wall 323 can maintain a predetermined shape. 【0212】 The mouthpiece 400 is configured such that a tuft 329 or bristle 324 engages with the tooth surface of a tooth in the dental arch, or, in the case of one or more dental positions where a tooth may be missing, the tuft 329 or bristle 324 engages with the gums at each dental position when the pressure in the pressure chamber 335 is increased. In particular, if a tooth may be missing at a given dental position, the tuft 329 of the bristle at the free end of the recessed wall leg 333 will engage with the gums at the empty dental position. 【0213】 When viewed along the longitudinal direction Z of the dental arch (as defined in Figure 21), the tufts 329 of the bristle 324 can be arranged at approximately the same density as when viewed in the cross-sections shown in Figures 23a and 23b. 【0214】 Referring to Figures 23a and 23b, when the pressure in the pressure chamber 335 is increased to an increased pressure state, for example by supplying fluid to the pressure chamber 335 or by increasing the amount of fluid in the pressure chamber 335, the recess wall 323 is so compacted, so to speak, narrowing the recess 322, thereby allowing the bristle 324 (in particular its free end) to firmly engage with the tooth surface and / or to contact and deform the tooth surface; the situation in Figure 23b (teeth not shown). When the pressure in the pressure chamber 335 is subsequently decreased, the recess wall is so widened, so to speak, enlarging the recess 322; the situation in Figure 23a (again, teeth not shown). While the narrowing and widening of this recessed wall may be small, when it is repeated alternately at some frequency between 0.5 Hz and 20 Hz, alternating deformation of this recessed wall by alternately narrowing and widening it causes the bristle to move between a tighter engagement with the tooth surface and a relatively looser engagement, and / or alternating between a first and second deformation state, which causes sweeping and / or rubbing of the bristle along the tooth surface. 【0215】 An effective brushing action of the mouthpiece can be achieved by appropriate cycles of increasing and decreasing the pressure in the pressure chamber 335. The bristle 324 attached to the bottom of the recessed wall 334 generally performs upward and downward motion during such cycles, while the bristle 324 at the leg of the recessed wall 333 generally performs lateral motion back and forth across the user's teeth in the x-axis direction, as defined in Figure 21, during such cycles. 【0216】 As merely an example to provide some indication of dimensions, and referring to Figure 21, for adults, the width of the tooth elements in the X direction varies between approximately 2 mm and 12 mm, depending on the dental position. Taking into account the desire to keep the mouthpiece as small as possible, the internal width of the U-shaped recess wall in the X direction should be kept as small as possible, and can be approximately 0 mm to 4 mm wider than the width of each tooth. As an example to provide some indication of dimensions, the internal width of the U-shaped recess wall can range from 0 mm to 20 mm when viewed in the X direction in Figure 21, and can range, for example, from 2 mm to 12 mm. The bristle can be up to 6 mm in length. In the example, the bristle is 3 mm to 4 mm in length, which means that there is no gap remaining between the bristles extending from the opposing recess wall legs 333, or a limited amount of gap of approximately 2 mm to 4 mm remains. In Figure 23, these gaps are shown in an exaggerated manner. Furthermore, as an example to provide some indication of dimensions, the U-shape of the recessed wall can have an internal height ranging from 3 mm to 20 mm when viewed in the Y direction in Figure 21, for example, from 5 mm to 10 mm. These internal width and internal height measurements are given for adults. These measurements may differ for children or animals. 【0217】 The pressure in the pressure chamber 335 is increased and decreased by a pump unit. Different combinations of pump units and valves are possible. Herein, one possible embodiment is described with reference to Figure 24. Figure 24 schematically shows a dental cleaning device 500 in a partially cutaway perspective view, including a handle member 502 and a mouthpiece 400 (for example, a mouthpiece as described above) connected thereto. The handle member 502 is provided with a handle interface, and the mouthpiece 400 is provided with a mouthpiece interface, which is configured to be detachably connected to the handle interface. The handle member 502 includes a battery 510 for storing electrical energy, which can be supplied to the battery 510 through a battery charging interface 512. The battery 510 provides energy to the main pump unit 504, which includes a motor 516, a transmission 518, a crank piston 520, a piston pump 522, and optionally to the mouthwash pump 524, on the printed circuit board (PCB) 514. A mouthwash capsule 530 containing the mouthwash liquid may be removably housed in the handle member 502. The piston pump 522 may be a pneumatic pump. Instead of a piston pump, a diaphragm pump, a plunger pump, a membrane pump, or a bellows pump may also be used. The mouthwash pump 524 may be a hydraulic pump. 【0218】 The dental cleaning device 400 further includes a pressure sensor 540, which is located near the duct 542 and is illustrated here in a very schematic manner. The pressure sensor 540 is configured to measure a pressure representing the pressure in a pressure chamber and is also configured to produce a pressure signal representing said pressure. Thus, from the fluid pressure at the inlet of the duct 542, the pressure sensor 540 can estimate or determine the pressure in the pressure chamber. The pressure sensor 540 can communicate with a controller 524 (here integrated with PCB 514) so ​​that the controller 524 can receive a pressure signal from the pressure sensor 540. 【0219】 As already mentioned, the dental cleaning device 400 further includes a controller 524, which is here integrated with the PCB 514. The controller 524 is configured to generate a control signal based on the pressure signal it receives from the pressure sensor 540. The controller 524 can communicate with the pump unit 504, which is configured to receive the control signal from the controller 524. In response to the control signal received from the controller 524, the pump unit 504 delivers a volume (liters per minute) into and / or out of the pressure chamber, and this volume increases and decreases the pressure in the pressure chamber. When the control signal indicates that the pressure in the pressure chamber exceeds a predetermined upper threshold, the volume delivered by the pump unit 504 is reduced, allowing the pressure in the pressure chamber to decrease again and fall below the threshold. 【0220】 Therefore, the operation of the dental cleaning device 500 is controlled by PCB 514, which includes a controller 524. PCB 514 controls the operation of a pump unit 504, which includes a motor 516. PCB 514 controls the dental cleaning device 500 and alternately increases and decreases the pressure in at least one pressure chamber supplied to the mouthpiece 504 by controlling the amount of fluid delivered into and out of the pressure chamber by the pump unit 504. 【0221】 This control of the pressure in the pressure chamber by providing a predetermined delivery rate is illustrated more graphically with reference to Figure 25. What can be seen in Figure 25 is a sinusoidal line, which can represent the fluctuations resulting from the reciprocal increase and decrease of the pressure in the pressure chamber. The horizontal lines indicate the upper threshold TU and the lower threshold TL. The upper threshold TU can be, for example, at most 2 bar above the ambient pressure, and can be, for example, at most 1 bar, at most 0.3 bar, or at most 0.2 bar above the ambient pressure. The lower threshold TU can be, for example, at most -1 bar above the upper threshold TU, and can be, for example, at most -0.4 bar above the upper threshold TU. The lower threshold TL can be in the range of -0.5 bar to +0.2 bar (for example, up to 0 bar) above the ambient pressure. According to the present invention in Chapter 2, when the pressure exceeds the upper threshold TU, the delivery rate of the pump is reduced. When the pressure drop falls below the lower threshold TL, the pump delivery rate may be increased. 【0222】 Starting from the left side of Figure 25, at timestamp t0, fluid is being pumped into the pressure chamber, increasing the pressure within it. Approximately two normal pressurization cycles are shown, in which the pressure is between the upper threshold TU and the lower threshold TL. The pump operates at frequency f, which can be derived from the time between two consecutive pressure peaks (during normal pump operation). The normal delivery amount D1 represents the amount of fluid pumped into the pressure chamber between the lower and upper pressure peaks (during normal pump operation). For example, depending on the fit of the dental cleaning device to the user's dental arch (or portion thereof) and the occlusal pressure applied by the user, the pressure always remains between the upper threshold TU and the lower threshold TL. In fact, this scenario is shown for the first two pressurization cycles. However, the exact pressures relative to the upper threshold TU and lower threshold TL may vary for each individual user, as indicated by arrow B. 【0223】 At timestamp t1, the pressure inside the pressure chamber suddenly increases sharply. This can be caused, for example, by the movement of the dental cleaning device from a position near the incisors (which are typically relatively narrow) to a position near the molars (which are typically relatively wide). As the teeth become wider between the recesses, the size of the pressure chamber decreases, increasing the pressure inside it. Alternatively, such a sudden increase in pressure can be caused, for example, by an increase in the user's occlusal pressure and / or an increase in the force with which the dental cleaning device is pressed over the teeth by the user. 【0224】 After a short time, the dental cleaning device responds to this pressure increase by reducing the pump delivery rate D2. In this example, the reduction in delivery rate is sufficient to bring the pressure just below the upper threshold TU (within a single pressurizing cycle), although this may require two or more pressurizing cycles, for example, two, three, or four. It should be further noted that the pump unit's response here lags somewhat behind the occurrence of the pressure increase. 【0225】 After reducing the delivery amount D2 by 1 degree and achieving the desired effect of reducing the pressure below the upper threshold TU, normal operation resumes with the same delivery amount D1 as before timestamp t1. 【0226】 In the example in Figure 25, a sharp drop in pressure within the pressure chamber is observed at timestamp t2. This can occur, for example, when the dental cleaning device is moved from a position near the molars to a position near the incisors, and / or when the applied pressure exerted by the user is reduced, and / or when the occlusal pressure exerted by the user is reduced. 【0227】 The dental cleaning device responds to this pressure decrease by increasing the pump delivery rate D3. In this example, the increase in delivery rate is insufficient to immediately bring the pressure well above the lower threshold TL. Therefore, the increased delivery rate D3 is maintained until the pressure in the pressure chamber returns to a sufficient level. In this example, the pump unit's response is somewhat delayed, here after the occurrence of the pressure decrease, and it only responds when the pressure drops significantly below the lower threshold TL. It is conceivable that the response would be faster, and that it would already be responding as soon as a sharp drop in pressure is noticed (perhaps even before the lower threshold is reached). 【0228】 In the embodiment shown in Figure 25, the pressure is increased until the lowest pressure experienced during the pressurization cycle exceeds the lower threshold TL. In some cases, the pressure is simply increased to a level where the maximum pressure during the pressurization cycle is between the upper threshold TU and the lower threshold TL. In that case, only one increased delivery amount D3 may be required. 【0229】 Preferably, it should be noted that the operating frequency of the pump unit does not change when the amount of fluid delivered changes. The operating frequency of the pump unit remains at a predetermined frequency, which can be in the range of 0.5 Hz to 20 Hz, and can be a fixed value or can vary as a function of time. 【0230】 Figure 26 provides a very schematic illustration of how the walls 533 and bristle of the dental cleaning device move toward the user's teeth after the pressure inside the pressure chamber is increased. The ends of the bristle are deformed and rub against the teeth, and this rubbing action removes plaque from the teeth. 【0231】 The following clauses 40-64 provide examples of the inventions of Chapter 2 described above, and further aspects and embodiments of these Chapter 2 inventions: 40] A dental cleaning device for brushing multiple dental positions simultaneously, - A mouthpiece having a pressure chamber and a recess, wherein the recess has a U-shaped cross-section and is bounded by flexible and / or deformable recess walls, and the pressure chamber is configured to contain a fluid under pressure; - A plurality of bristles, optionally, each attached to the recess wall by one end thereof and extending from the recess wall into the recess; - A pump unit disposed in fluid communication with the pressure chamber, configured to pump a predetermined volume of fluid into and out of the pressure chamber, thereby reciprocatingly increasing and decreasing the pressure inside the pressure chamber between an increased pressure state and a decreased pressure state, thereby deforming the recess wall, causing the recess wall to reciprocate and move, and increasing and decreasing the recess, respectively; Includes, Dental cleaning devices are - A pressure sensor configured to measure the pressure representing the pressure inside a pressure chamber, and also configured to produce a pressure signal representing the said pressure, - A controller configured to generate control signals, Including; The pressure sensor and controller are connected so that the controller receives a pressure signal from the pressure sensor when in use, and the controller and pump unit are connected so that the pump unit receives a control signal from the controller when in use; The controller is configured to generate a control signal based on a pressure signal, and the pump unit is configured to deliver a predetermined amount into and / or out of the pressure chamber in response to the control signal; A dental cleaning device in which the controller is configured to reduce the amount delivered by the pump unit when the pressure in the pressure chamber exceeds a predetermined upper threshold. 41] The dental cleaning device according to Clause 40, wherein the pump unit has a predetermined operating frequency, and the controller is configured to prevent changes in the operating frequency in order to reduce the amount delivered by the pump unit when the pressure in the pressure chamber exceeds a predetermined upper threshold. 42] The pump unit has a predetermined operating frequency, - The controller is configured to operate the pump unit in response to pressure changes at a predetermined operating frequency, or, - The dental cleaning device according to Clause 40 or 41, wherein the pump unit is configured to operate at a predetermined operating frequency. 43] The dental cleaning device according to any one of the clauses 40 to 42, wherein the pump unit has an operating frequency that changes according to a predetermined function of the time measured after the pump unit is switched on. 44] The dental cleaning device according to any one of the clauses 40 to 42, wherein the pump unit has an operating frequency that is a fixed predetermined value. 45] The dental cleaning device according to any one of the clauses 40 to 44, wherein the operating frequency is in the range of 0.5 Hz to 20 Hz. 46] The dental cleaning device according to any one of the clauses 40 to 45, wherein the upper threshold is at most 2 bar relative to ambient pressure, for example, at most 1 bar relative to ambient pressure. 47] The dental cleaning device according to any one of the clauses 40 to 46, wherein the upper threshold is at most 0.3 bar relative to ambient pressure, for example, at most 0.2 bar relative to ambient pressure. 48] The dental cleaning device according to any one of the clauses 40 to 47, wherein the controller is further configured to increase the delivery rate of the pump unit when the pressure in the pressure chamber falls below a predetermined lower threshold. 49] The dental cleaning device according to Clause 48, wherein the lower threshold is below the upper threshold and in a range up to 1 bar, for example, up to 0.4 bar. 50] The dental cleaning device according to Clause 48 or 49, wherein the lower threshold is in the range of -0.5 bar to +0.2 bar relative to ambient pressure, for example, in the range of -0.5 bar to 0 bar relative to ambient pressure. 51] A dental cleaning device for brushing multiple dental positions simultaneously, - A mouthpiece having a pressure chamber and a recess, wherein the recess is bounded by a recess wall, the recess wall having a curved longitudinal and transverse U-shaped cross-section relative to the longitudinal direction, the recess wall is configured to encompass a dental position in the range from at least the left second premolar to at least the right second premolar when viewed in the curved longitudinal direction, and the pressure chamber is configured to contain a fluid under pressure; - Optionally, a plurality of bristles, each having one end attached to the recess wall and extending into the recess away from the recess wall; - A pump unit is arranged in fluid communication with the pressure chamber, and is configured to reciprocately increase and decrease the pressure inside the pressure chamber between an increased pressure state and a decreased pressure state by pumping a predetermined volume of fluid into and out of the pressure chamber, thereby deforming the recessed wall, moving the recessed wall back and forth, and increasing and decreasing the recess, respectively. The pump unit operates at a predetermined operating frequency during operation. Includes, A dental cleaning device with a specified operating frequency in the range of 0.5 Hz to 20 Hz. 52] The dental cleaning device according to Clause 51, wherein the specified operating frequency is in the range of 1 Hz to 15 Hz, for example, in the range of 3 Hz to 10 Hz. 53] The dental cleaning device according to Clause 51 or 52, wherein the specified operating frequency is a fixed frequency. 54] The dental cleaning device according to clause 51 or 52, wherein the predetermined operating frequency varies according to a predetermined function of the time measured after the pump unit is switched on. 55] A dental cleaning device according to any one of the clauses 40 to 54, wherein when the pressure in the pressure chamber is increased during use, the bristle moves toward the user's dental position, and at the same time, the end portion of the bristle is deformed and rubbed against the teeth, and this rubbing action of the end portion cleans the teeth. 56] The dental cleaning device according to any one of the clauses 40 to 55, wherein the recess walls of the recesses and / or at least some of the bristle are made of a material having a hardness of 20 Shore A to 100 Shore A, for example, 50 Shore A to 80 Shore A. 57] The dental cleaning device according to any one of the clauses 40 to 55, wherein the recess walls of the recesses and / or at least some of the bristle are made of a material having a hardness of 50 Shore D to 100 Shore D, for example, 70 Shore D to 90 Shore D. 58] The dental cleaning device according to any one of the clauses 40 to 57, wherein the mouthpiece has two recesses, each having a U-shaped cross-section and being bounded by the wall of the recess, and the openings of the U-shaped cross-sections of the two recesses are facing in opposite directions from each other. 59] The dental cleaning device according to any one of the clauses 40 to 58, wherein the recess or two recesses each have an elongated curved shape and are configured to encompass at least five dental positions of the user, for example, dental positions in the range from the left first molar to the right first molar. 60] The pump unit includes a pump selected from the group consisting of a piston pump, a diaphragm pump, a plunger pump, a membrane pump, or a bellows pump, as described in any one of the dental cleaning devices described in any one of the clauses 40 to 59. 61] Dental cleaning devices are - A pressure sensor configured to measure the pressure representing the pressure inside a pressure chamber, and also configured to produce a pressure signal representing the said pressure, - A controller configured to generate control signals, Including; The pressure sensor and controller are connected so that the controller receives a pressure signal from the pressure sensor when in use, and the controller and pump unit are connected so that the pump unit receives a control signal from the controller when in use; The controller is configured to generate a control signal based on a pressure signal, and the pump unit is configured to deliver a predetermined amount into and / or out of the pressure chamber in response to the control signal; The dental cleaning device according to any one of clauses 15 to 60, wherein the controller is configured to reduce the delivery volume of the pump unit when the pressure in the pressure chamber exceeds a predetermined upper threshold. 62] A dental cleaning device as described in Clause 58 in combination with any one of Clauses 46 to 50. 63] A method for operating a dental cleaning device for brushing multiple dental positions simultaneously, wherein the cleaning device is - A mouthpiece having a pressure chamber and a recess, wherein the recess is bounded by a recess wall, the recess wall having a curved longitudinal and transverse U-shaped cross-section relative to the longitudinal direction, the recess wall is configured to encompass at least a portion of the user's dental arch when viewed in the curved longitudinal direction, and the pressure chamber is configured to contain a fluid under pressure; - Optionally, a plurality of bristles, each having one end attached to the recess wall and extending into the recess away from the recess wall; - A pump unit is arranged in fluid communication with the pressure chamber, and is configured to pump a predetermined volume of fluid into and out of the pressure chamber, thereby reciprocatingly increasing and decreasing the pressure inside the pressure chamber between an increased pressure state and a decreased pressure state, thereby deforming the recessed wall, moving the recessed wall back and forth, and increasing and decreasing the recess, respectively. Includes, - When the pressure in the pressure chamber exceeds a predetermined upper threshold, the delivery volume of the pump unit is reduced; and / or, - The pump unit operates at an operating frequency in the range of 0.5 Hz to 20 Hz. 64] - When the pressure in the pressure chamber exceeds a predetermined upper threshold, the pump unit is operated in such a manner that a change in operating frequency is prevented; and / or, - The pump unit operates at a fixed operating frequency; and / or, - The pump unit operates at an operating frequency in the range of 1Hz to 15Hz, for example, in the range of 3Hz to 10Hz; and / or, - The upper threshold is at most 2 bar relative to the ambient pressure, for example, at most 1 bar; and / or, - The upper threshold is at most 0.3 bar relative to the ambient pressure, for example, at most 0.2 bar; and / or, - The pump unit's delivery rate is increased when the pressure in the pressure chamber drops below a predetermined lower threshold: ○ The lower threshold is below the upper threshold, in a range of up to 1 bar, for example, up to 0.4 bar; and / or, ○ The lower threshold is in the range of -0.5 bar to +0.2 bar relative to the ambient pressure, for example, in the range of -0.5 bar to 0 bar; and / or, - The pump unit operates at an operating frequency that changes according to a predetermined function of the time measured after the pump unit is switched on, as described in Clause 63. 【0232】 As can be seen from the above, the term “pressure chamber,” as used throughout this Chapter 2, refers to a chamber in which the pressure changes between a reduced pressure state and an increased pressure state. Both the reduced pressure state and the increased pressure state can be pressures below ambient pressure, i.e., a vacuum, defined as a pressure between 0 bar and 1 bar. Alternatively, both the reduced pressure state and the increased pressure state can be pressures above ambient pressure, or one of these pressure states can be approximately ambient pressure, while the other is either below or above ambient pressure. 【0233】 In this Chapter 2, where the term “pressure in a pressure chamber” or similar terminology is used, it refers to “pressure of the fluid in a pressure chamber.” This is the pressure of the fluid acting on the recessed walls to cause a brushing action. The fluid pressure can be increased, for example, by supplying additional fluid into the pressure chamber, or decreased by allowing the fluid to leave the pressure chamber. 【0234】 Taking into account various dental positions and natural tooth shapes, the shape of the U-shaped cross section can vary along the length of the recess / recess wall. In the region of the upper and / or lower incisors, the U-shaped cross section can be, for example, V-shaped. 【0235】 Chapter 3 [Title of Invention] Mouthpiece for brushing at multiple dental positions, brushing device including such mouthpiece, and method for operating such mouthpiece or brushing device 【0236】 Chapter 3 of the present invention relates to the field of dental cleaning devices, and more particularly to a mouthpiece for brushing multiple dental positions simultaneously. Chapter 3 of the present invention further relates to a brushing device including a mouthpiece according to the present invention of Chapter 3. Furthermore, Chapter 3 of the present invention relates to a method for operating such a mouthpiece or brushing device. The mouthpiece is configured to brush at least five dental positions simultaneously. 【0237】 [Background Technology for Chapter 3] Cleaning the teeth of humans and animals is essential for oral hygiene and internal health. Various dental cleaning devices are available, such as manual and electric toothbrushes. These typical toothbrushes recommend brushing teeth in a prescribed manner for at least two minutes a day to effectively remove plaque. However, the average person does not spend the entire prescribed time cleaning their teeth, nor do they always brush according to an effective method. Additionally, brushing teeth with a toothbrush can be difficult for people with disabilities, the elderly, or children. This is because typical toothbrushes require precise positioning of the brush bristles on the various surfaces of the teeth. Furthermore, people may apply excessive pressure to the brush bristles while brushing, which not only causes rapid and excessive wear of the bristles but also renders the brushing process ineffective, potentially damaging teeth and causing gum recession, which has detrimental effects on dental health. 【0238】 As is common in older adults, when teeth are missing in some or all dental locations, cleaning the gums in these locations remains an essential condition for oral hygiene and internal health. 【0239】 To clean the teeth and / or gums in these dental locations, there is a need for automatic brushing of the teeth and / or gums in those dental locations, thereby reducing the time and effort required for effective brushing. In addition, there is a need to avoid the need to carefully manipulate the brush. 【0240】 Dental cleaning devices are known that include mouthpieces that cover both the maxillary and mandibular dental arches. Such mouthpieces have brushing surfaces with bristle-like structures that move automatically to clean a complete set of teeth. 【0241】 The mouthpieces and brushing surfaces of known dental cleaning devices require adjustment to closely fit the shape of the user's dental arch. The mouthpiece should be able to clean all tooth surfaces. However, dental arches vary considerably among different users due to differences in arch size, malocclusion, and missing teeth. Therefore, there is a need for dental cleaning devices with adjustable mouthpieces. 【0242】 Reference Patent Document 1 discloses an electric dental cleaning device with a mouthpiece. This known mouthpiece has an upper part for cleaning the maxillary / upper dental arch and a lower part for cleaning the mandibular / lower dental arch. Both the upper and lower parts of this known mouthpiece have brush pads, each having a U-shaped cross section and an upper bristle inside the U-shape. These two brush pads are positioned with the U-shaped bottoms of the pads facing each other, and the U-shaped legs of the upper brush pad pointing upward opposite to the U-shaped legs of the lower brush pad (which point downward). The brush pad includes a rigid brush plate on the outside of the U-shape, leg plates at each leg, and a bottom plate transverse to the leg plate at the bottom of each U-shape. These U-shaped brush pads are driven up and down relative to the free end / upper part of the tooth in the direction of the U-shaped legs. In some embodiments, the bladder may be positioned between the maxillary and mandibular arches of the mouthpiece, i.e., between the bottom plates, and alternating or vibrating pneumatic pressure and suction forces are applied to this bladder, making it possible to move the bottom plates relative to each other, which causes the up and down movement of the U-shaped brush pad, thereby brushing the teeth. 【0243】 In one embodiment of a mouthpiece according to Patent Document 1 of the referenced literature, the mouthpiece is adjustable in that the lateral / leg brush plates are positioned relative to the lingual and faculties of the teeth by the use of flexible fingers and / or bladder, and the flexible fingers and / or bladder are configured to apply static pressure and move up and down along the lingual and faculties of the teeth in a predetermined direction, transversely to the direction of the static pressure, to engage the tips of the bristle of the brush plates with the lingual and faculties of the teeth. 【0244】 In Patent Document 1, the brushing movement is simply a 1D movement (one-dimensional movement). This is because the U-shaped brush pads are only moved toward and away from each other. 【0245】 The mouthpiece described in Patent Document 1 has the disadvantage of having a limited brushing action. The reason is that the bristle on the brush pad is mounted on a rigid plate, which limits their ability to reach all surfaces of the tooth. 【0246】 Reference Document 2 (which has the corresponding European Patent Application Publication No. 0173114) discloses several embodiments of a device for cleaning teeth, which can be divided into two types of devices, each intended to encompass one tooth at a time for cleaning one tooth at a time, so to speak. The first type of device ensures static brushing pressure of the bristle against the tooth while the brushing movement of the bristle is caused by hand, i.e., the brush head is mounted on a handgrip, which is operated to move the brush head along the tooth like a normal toothbrush. In this first type, one single pressure chamber or two opposing pressure bubbles may be used to ensure that the cleaning contact pressure between the individual bristle tuft and the tooth is at least approximately equal throughout. In the first type, the brushing movement of the tuft is caused by hand, whereas in the second type, the brushing movement of the device is automated by a drive. A second type of device (shown in Figures 10-21 of Patent Document 2) is designed so that the tuft is driven to perform 2D movement (two-dimensional movement) relative to the tooth surface. Each tuft is driven to move in a plane perpendicular to the dental arch (i.e., perpendicular to the tooth being cleaned). In the first stage, the tuft is moved toward the tooth to press against it, then the tuft is moved along the tooth surface in the direction of the tooth axis toward the top / crown of the tooth, followed by moving the tuft away from the tooth to reduce pressure, and then moving the tuft back toward the tooth axis toward the gum to initiate the next cycle. In this second type, a pressure bubble may be used to drive the tuft to perform this 2D movement. In these embodiments, the tuft is mounted on a rigid cleaning element carrier, and the pressure bubble acts on the rigid cleaning element carrier directly or indirectly via a rocker arm. 【0247】 The automated mouthpiece described in Patent Document 2 has the disadvantage of having a limited brushing action. This is because the tuft is mounted on a rigid carrier, which limits the tuft's ability to reach all surfaces of the tooth. A further disadvantage of this mouthpiece is that only one tooth is cleaned at a time in the automated manner, and in order to clean all teeth, the automated mouthpiece of Patent Document 2 must be moved manually along all teeth, which is time-consuming. 【0248】 Therefore, there remains a need for automated dental cleaning devices that are quick and thorough when cleaning multiple teeth simultaneously. There also remains a need for automated dental cleaning devices that require as little effort as possible from the user. Furthermore, there remains a need for automated dental cleaning devices that effectively reach virtually all tooth surfaces. 【0249】 Further reference is made to Patent Document 3, filed by the applicant on April 27, 2018. This Patent Document 3 has not yet been published as of the priority date of this application; i.e., Patent Document 3 is unpublished. The mouthpiece according to this earlier application of the applicant is capable of brushing all teeth of the upper and lower dental arches in a single pass and has at least one pressure chamber comprising a flexible wall component provided with bristle. The flexible wall component is configured to be deformable by alternately increasing and decreasing the pressure of the fluid in the pressure chamber. [Prior art document] [Patent] 【0250】 [Patent Document 1] U.S. Patent Application Publication No. 2010 / 0062397 Specification [Patent Document 2] U.S. Patent No. 4,795,347 [Patent Document 3] International Application No. PCT / NL2018 / 050276 【0251】 [Summary of the Inventions in Chapter 3] The object of the present invention in Chapter 3 is to provide an alternative mouthpiece, in particular an automatic brushing device, for brushing at multiple dental locations. A further object of the present invention in Chapter 3 is to provide an improved mouthpiece for brushing at multiple dental locations, and a brushing device provided with the improved mouthpiece. Another further object is to provide a mouthpiece for brushing at multiple dental locations, and a brushing device including such a mouthpiece, which overcomes one or more of the disadvantages of brushing mouthpieces and brushing devices known from the prior art. More specifically, the present invention in Chapter 3 is to provide a mouthpiece with an improved brushing action, such as one of the unpublished Patent Documents 3 or 1 from the applicant. 【0252】 According to a first aspect of the present invention in Chapter 3, one or more of the above-mentioned objectives are achieved by providing the mouthpiece according to claim 65, which has a preamble known from unpublished patent document 3. 【0253】 According to the present invention in Chapter 3, a mouthpiece is provided for brushing multiple dental positions simultaneously. In other words, a mouthpiece is provided that is configured to brush multiple dental positions simultaneously. If natural or artificial tooth elements are present in the dental positions that the mouthpiece brushes, these tooth elements are brushed. If no tooth elements are present in the dental positions that the mouthpiece brushes, the gums may be brushed. 【0254】 The mouthpiece according to the present invention in Chapter 3 includes a body portion provided with at least one recess, which can be one or two recesses. This at least one recess has a U-shaped cross-section in a curved longitudinal direction and transversely to the longitudinal direction, and is configured to encompass a plurality of at least five dental positions when viewed in the curved longitudinal direction. The body portion includes a flexible recess wall for each of the recesses that defines the boundary of each recess. The recess wall can be a sheet, which may be made of, for example, plastic, such as polyethylene, polypropylene, polyester, or nylon, or elastomer, such as thermoplastic elastomer or silicone elastomer. The recess wall may be lined with a plurality of bristles, each having one end attached to the recess wall and extending from the recess wall into the recess. In other words, the body portion has a recess, and the wall of the recess may be covered by bristles distributed across the wall of the recess. At least five dental locations (the elements of teeth at these locations, or the gums covering the jawbone at the location of those dental locations) can be accommodated within the recess, and if present, the bristle within the recess will be able to brush at least five dental locations simultaneously. The bristle can be made from nylon, elastomer, or any other suitable material. In the case of dentitionless dental arches, the remaining arch of the gums may also require treatment. In this case, the gums can be massaged by the recess walls without bristle. For improved gum cleaning, a cleaning fluid may be used in such a mouthpiece without bristle. 【0255】 According to the present invention in Chapter 3, the main body is provided with at least one pressure chamber configured to contain a fluid under pressure, the pressure of which can be increased and decreased. The main body is configured to deform a recessed wall by reciprocating the pressure in at least one pressure chamber, causing a continuous and repeated reciprocating motion of the recessed wall and a bristle (optionally provided above the recessed wall). Thus, the main body includes one, two, three, four, five, six, or any other number of pressure chambers that can be filled with fluid, as described in Patent Document 3, which is under the name of the same applicant and has not yet been published as of the priority date of this application. By reciprocating, increasing the pressure in at least one of the pressure chambers from a reduced pressure state to an increased pressure state, and decreasing the pressure in this pressure chamber from an increased pressure state to a reduced pressure state, and by continuously repeating this reciprocating motion, the recessed wall (optionally bearing the bristle) is moved, resulting in the recessed wall and the bristle acting on an object (teeth and / or gums present in these dental locations) at the dental location to clean the object. 【0256】 Regarding the technical terms "increased pressure state" and "decreased pressure state," it should be noted that these states are related to each other; that is, in a decreased pressure state, the pressure is lower than in an increased pressure state. In both states, the pressure can be lower than, for example, atmospheric pressure. 【0257】 Atmospheric pressure is the pressure that permeates the room where the mouthpiece user is located when using the mouthpiece. Generally, atmospheric pressure is assumed to be an absolute pressure of approximately 1 bar, but the actual value of atmospheric pressure will depend, among other things, on altitude relative to sea level and meteorological conditions. 【0258】 According to the present invention in Chapter 3, the recessed wall is configured to be locally deformable, or in other words, to have such locally deformable properties, so that when the pressure in the pressure chamber or one or more of the at least one of the pressure chambers ("in the pressure chamber or one or more of the at least one of the pressure chambers" will be further named "in the at least one of the pressure chambers") is reciprocally increased and decreased, the shape of the recessed wall changes locally, in the increased pressure state, the bristle (or, if the bristle is not present, the recessed wall) is pressed against the dental position and the shape of the recessed wall is locally adjusted to the local shape of the dental position enclosed by the recessed wall, whereas in the decreased pressure state, the shape of the recessed wall is not as locally adjusted to the local shape of the dental position enclosed by the recessed wall as in the increased pressure state. Therefore, the recessed wall can initially have a smooth surface (without considering the bristle), which changes into an uneven surface as the locally deformable recessed wall is pressed, so to speak, against the irregular contours of the dental position (without considering the bristle between them) when the pressure is increased. Therefore, the recessed wall is locally shaped to the dental position at that location. This shaped adjustment under increased pressure can be a fit adjustment (in which case the shape of the recessed wall is, so to speak, identical to the contour of the dental position), but it does not have to be, and in fact may not be. When the pressure is decreased, the recessed wall returns to its initial state and takes on a shape that is not locally shaped (compared to the shaped adjustment under increased pressure). This locally unadjusted shape may be shaped to some extent to the local shape of the tooth contour, but the adjustment will be less pronounced. This change in the shape of the recessed wall between the locally adjusted and locally unadjusted shapes results in the bristle being able to reach the interdental space better and results in additional movement of the bristle in addition to the movement already caused by increasing and decreasing the pressure in at least one pressure chamber. This additional movement results in an additional sweeping effect of the bristle. In summary, the change in the shape of the recessed wall between the locally regulated and unregulated shapes results in an improved brushing action. 【0259】 According to a further embodiment of the first aspect of the present invention in Chapter 3, when viewed longitudinally along the lingual and facial sides of the dental position encompassed by the recessed wall, the recessed wall may have less relief under reduced pressure conditions than under increased pressure conditions. 【0260】 According to further embodiments of the first aspect of the present invention in Chapter 3, the local deformability of the recess wall may be configured such that the local change in the shape of the recess wall between an increased pressure state and a decreased pressure state occurs within a pressure difference in the range of up to 2 bar, for example, up to 0.4 bar, where the pressure difference is defined as the pressure in the pressure chamber in the decreased pressure state minus the pressure in the pressure chamber in the increased pressure state. The expression "pressure difference in the range of up to x bar" means a pressure difference such as from zero (not including zero) to x bar (including x bar). Maintaining the pressure difference between the increased pressure state and the decreased pressure state below 2 bar prevents the user from experiencing an unbearable pressure difference. Maintaining the pressure difference below 0.4 bar results in the pressure difference between the increased pressure state and the decreased pressure state being experienced by the user as generally acceptable. The local deformability of the recess wall may be configured such that local changes in the shape of the recess wall occur between increased and decreased pressure conditions at pressure differences in the range of up to 0.2 bar (or even lower pressure differences). 【0261】 According to a further embodiment of the first aspect of the present invention in Chapter 3, the pressure in the at least one pressure chamber can be higher than atmospheric pressure in a reduced pressure state. 【0262】 Atmospheric pressure is the pressure that permeates the room where the mouthpiece user is located when using the mouthpiece. Generally, atmospheric pressure is assumed to be an absolute pressure of approximately 1 bar, but the actual value of atmospheric pressure will depend, among other things, on altitude relative to sea level and meteorological conditions. 【0263】 According to a further embodiment of the first aspect of the present invention in Chapter 3, the pressure in the at least one pressure chamber can be at most 2 bar relative to atmospheric pressure in an increased pressure state, for example, at most 1 bar relative to atmospheric pressure. 【0264】 According to a further embodiment of the first aspect of the present invention in Chapter 3, the pressure in the at least one pressure chamber can be at most 0.3 bar relative to atmospheric pressure in an increased pressure state, for example, at most 0.2 bar relative to atmospheric pressure. At a maximum pressure of 0.3 bar, the brushing action is satisfactory, while minimizing the risk of harm or injury in cases where the recesses may rupture. At a maximum pressure of 0.2 bar, the brushing action is still satisfactory. 【0265】 According to a further embodiment of the first aspect of the present invention in Chapter 3, the pressure in the at least one pressure chamber is lower than atmospheric pressure in the reduced pressure state. 【0266】 According to a further embodiment of the first aspect of the present invention in Chapter 3, the pressure in the at least one pressure chamber can be in the range of -0.5 bar to +0.2 bar relative to atmospheric pressure in a reduced pressure state, for example, in the range of -0.5 bar to 0 bar relative to atmospheric pressure. A reduced pressure of at least -0.5 bar reduces the likelihood of damage to the recess wall. The reduced pressure can be in the range of -0.4 bar to -0.25 bar relative to atmospheric pressure. A reduced pressure in the range of -0.4 bar to -0.25 bar relative to atmospheric pressure can be realized by relatively inexpensive means. A reduced pressure with a value below zero relative to atmospheric pressure means that a vacuum is generated in the pressure chamber when the pressure is reduced to the reduced pressure state. Using a pressure below atmospheric pressure with respect to the reduced pressure state means that the likelihood of damaging the user's gums is significantly reduced. 【0267】 According to a second aspect of the present invention in Chapter 3 (which may be separate from or combined with one or more other aspects of the present invention in Chapter 3), the present invention in Chapter 3 provides a mouthpiece for brushing multiple dental positions simultaneously, as expressed in independent claim 73. To define this second aspect, a system of three mutually orthogonal axes is defined, including the x, y, and z axes, where the z axis is a curved axis that follows the contour of the dental arch (e.g., the dental arch of an adult), the x and y axes are perpendicular to each other and define the xy plane, the xy plane is flat and perpendicular to the curved z axis. The mouthpiece of this second aspect includes a body portion provided with at least one recess. Also, as with the other aspects of the present invention in Chapter 3, the mouthpiece will be inserted into the user's mouth when in use. Therefore, the dimensions of the mouthpiece may be configured to allow insertion into the user's mouth. At least one recess has a curved longitudinal direction extending parallel to the z-axis and a U-shaped cross-section transverse to the longitudinal direction, and is configured to encompass a plurality of at least five dental positions when viewed in the curved longitudinal direction. The main body includes a recess wall for each recess, the recess wall defining the boundary of each recess, and provides a plurality of bristles. Also, as in other embodiments of the invention in Chapter 3, the bristles can be flexible and / or deformable. Each bristle has a fixed end, which is attached to the main body in the recess wall. The fixed end of the bristle may be attached, for example, to the recess wall, but may also be attached to another part of the main body. Each bristle extends from the fixed end into the recess toward the free end of the bristle, which is located in the recess.According to this second embodiment, the main body is configured to reciprocately expose the multiple fixed ends of the bristle (for example, each free end of each bristle) to a first reciprocating pivotal movement around a first pivot axis, a second reciprocating pivotal movement around a second pivot axis, and a reciprocating translational movement along a translation axis, when the multiple dental positions are contained within the recesses, wherein the first pivot axis, the second pivot axis, and the translation axis are perpendicular to each other, the first pivot axis is parallel to the z axis, and the second pivot axis and the translation axis extend in the xy plane. Configuring the body to expose the fixed end of the bristle to these movements can be achieved by the body, which includes a pressure chamber and recessed walls (which are locally deformable and support the fixed end of the bristle) (see also the following paragraph), but can also be achieved by different mountings of the fixed end of the bristle, and / or by different drives for exposing the fixed end of the bristle to these movements. 【0268】 According to further embodiments of the first and / or second aspects of the present invention in Chapter 3, the local deformability of the recess wall is such that when the pressure in the at least one pressure chamber is reciprocally increased and decreased, and when the plurality of dental positions are enclosed within the recess, each location of the recess wall is subjected to a first reciprocating pivot movement around the first pivot axis, a second reciprocating pivot movement around the second pivot axis, and a reciprocating translation movement along the translation axis, the first pivot axis, the second pivot axis, and the translation axis are perpendicular to each other. 【0269】 According to further embodiments of the first and / or second aspects of the present invention in Chapter 3, each bristle is located at the base of each bristle attached to a recess wall, and the local deformability of the recess wall allows the base of each bristle to be subjected to a first reciprocating pivot movement around a first pivot axis, a second reciprocating pivot movement around a second pivot axis, and a third reciprocating translation movement along a translation axis, where the first pivot axis, the second pivot axis, and the translation axis are perpendicular to each other. 【0270】 According to further embodiments of the first and / or second aspects of the present invention in Chapter 3, each bristle may be attached to the recess wall at a mounting point; at each mounting point, a local set of three mutually orthogonal axes may be defined, the local set including the x-axis, y-axis, and z-axis, where the z-axis is a curved axis defined by the curved longitudinal direction of the recess, and the x-axis and y-axis define an xy-plane perpendicular to the z-axis; the local deformability of the recess wall is such that the at least one pressure chamber When increasing and decreasing the internal pressure reciprocally, and when encompassing the plurality of dental positions within the recess, the mounting point may be subjected to one or more movements from a group consisting of a first reciprocating pivot movement around a first pivot axis, a second reciprocating pivot movement around a second pivot axis, and a reciprocating translation movement along a translation axis; the first pivot axis is parallel to the z axis, and the second pivot axis and translation axis are in the xy plane and perpendicular to each other. In addition to these first, second, and third reciprocating movements, the recessed wall may also enable fourth, fifth, and sixth reciprocating movements, which can further contribute to the brushing action. Here, it should be noted that, viewed at the base of the bristle, the fourth reciprocating movement is a reciprocating translational movement in the direction of the z-axis, the fifth reciprocating movement is a reciprocating translational movement in the direction of the y-axis, and the sixth reciprocating movement is a reciprocating rotational movement around the x-axis. 【0271】 According to further embodiments of the first and / or second aspects of the present invention in Chapter 3, the main body may be provided with two recesses, the openings of the U-shaped cross-sections of the two recesses facing in opposite directions from each other. This allows the upper and lower dental positions to be brushed simultaneously. 【0272】 According to further embodiments of the first and / or second aspects of the present invention in Chapter 3, the recess wall is U-shaped in the transverse direction with respect to the longitudinal direction, coinciding with the U-shaped cross-section of the recess; the U-shape of each recess wall defines two recess wall legs extending from the bottom of the recess wall, each leg having a free end; the free end of the leg is provided with an end bristle; the main body is, - When increasing the pressure in the at least one pressure chamber, the upper end of the leg is configured to shift from the inside of the recess to the outside of the recess, - When reducing the pressure in at least one pressure chamber, it is configured to reduce the vertical distance and to shift the upper end of the leg from outside the recess to inside the recess, When the pressure in at least one of the pressure chambers is reciprocated and decreased, the end bristle is subjected to reciprocating swivel movement around an axis parallel to the longitudinal direction. A "roller bellows function" is introduced. Shifting the ends of the legs back and forth from the inside to the outside of the recess causes the end bristle to perform reciprocating swivel movement around an axis parallel to the curved longitudinal direction. As a result, the tooth-to-gum transition is subjected to the special brushing action of these end bristle. As is generally known, these transitions require careful cleaning care. Furthermore, according to a third aspect of the present invention in Chapter 3, this “roller bellows functionality” may be applied separately from the first and / or second aspects of the present invention in Chapter 3, as can be expressed as follows, as in independent claim 79 (which is bounded to unpublished Patent Document 3): “A mouthpiece for brushing multiple dental positions simultaneously, comprising a body portion provided with at least one recess; the at least one recess having a curved longitudinal and transverse U-shaped cross section, and configured to encompass a plurality of at least five dental positions when viewed in the curved longitudinal direction; the body portion comprising, for each recess, a flexible recess wall defining the boundary of each recess, The wall is lined with a plurality of bristles, each having one end attached to the recess wall and extending from the recess wall into the recess; the main body provides at least one pressure chamber configured to contain fluid under pressure; the main body is configured to deform the recess wall by reciprocating the pressure in at least one pressure chamber between a reduced pressure state and an increased pressure state, the recess wall having a U-shape in the transverse direction with respect to the length direction, coinciding with the U-shaped cross section of the recess; the U-shape of each recess wall defines two recess wall legs extending from the bottom of the recess wall, each leg having a free end, and the main body is, - When increasing the pressure in the at least one pressure chamber, the upper end of the leg is configured to shift from the inside of the recess to the outside of the recess, - When reducing the pressure in the at least one pressure chamber, the upper end of the leg is configured to shift from the outside of the recess to the inside of the recess, A mouthpiece in which, when the pressure in at least one pressure chamber is reciprocatedly increased and decreased, the end bristle is subjected to reciprocating swivel movement about an axis parallel to the longitudinal direction. 【0273】 According to further embodiments of the first and / or second and / or third aspects of the present invention in Chapter 3, the main body may be configured to expose the legs of the recessed wall to vertical reciprocating movement when the pressure in the at least one pressure chamber is reciprocally increased and decreased. 【0274】 According to further embodiments of the first and / or second and / or third aspects of the present invention in Chapter 3, the main body may be configured to lengthen the legs when increasing the pressure in at least one pressure chamber and to shorten the legs when decreasing the pressure in at least one pressure chamber. Lengthening and shortening the legs moves the bristle on the legs in the longitudinal direction of the legs relative to the dental position. 【0275】 According to further embodiments of the first and / or second and / or third aspects of the present invention in Chapter 3, the main body defines a reference plane parallel to the curved longitudinal direction, the free ends of the legs point away from the reference plane, and the outer sides of the base face the reference plane; the vertical distance is defined as the distance from the reference plane to the free ends of the legs, measured in the transverse direction with respect to the reference plane; and the main body is - Further configured to increase the vertical distance when increasing the pressure in at least one of the pressure chambers, - Further configured to reduce the vertical distance when reducing the pressure in at least one of the pressure chambers. Increasing and decreasing the vertical distance moves the bristle on the leg in the direction of the distance perpendicular to the dental position. 【0276】 According to further embodiments of the first and / or second and / or third aspects of the present invention in Chapter 3, the mouthpiece may further include a meshwork fixed to a recessed wall, the meshwork being formed of nodes and mesh members, each of which extends from one node to another, each node connecting at least three of which mesh members to each other, and each node bearing one or more of which bristle or tufts of which bristle. This “mesh functionality” simplifies the production of the mouthpiece according to the present invention in Chapter 3. The mesh with bristle on the nodes may be produced as a separate component, separately from and prior to the production of the mouthpiece. During or after the production of the mouthpiece, the mesh with bristle may be positioned to lie on the recessed wall.According to a fourth aspect of the present invention in Chapter 3, this “mesh functionality” may also be applied separately from the first and / or second and / or third aspects of the present invention in Chapter 3, as can be expressed as follows, as in independent claim 83 (which is bounded to unpublished Patent Document 3): “A mouthpiece for brushing multiple dental positions simultaneously, comprising a body provided with at least one recess; the at least one recess having a U-shaped cross section in a curved longitudinal direction and transversely to the longitudinal direction, and configured to encompass a plurality of at least five dental positions when viewed in the curved longitudinal direction; the body comprising, for each of the recesses, a recess wall defining the boundary of each recess, the recess wall being lined by a plurality of bristles extending from the recess wall into the recess; the body optionally, fluid under pressure A mouthpiece may be provided comprising at least one pressure chamber configured to accommodate a main body, the main body being configured to optionally reciprocate, deform the recess wall by increasing the pressure in at least one pressure chamber from a reduced pressure state to an increased pressure state, and decreasing the pressure in at least one pressure chamber from an increased pressure state to a reduced pressure state; the mouthpiece further comprises meshwork, the meshwork lying in contact with the recess wall or fixed to the recess wall; the meshwork is formed of nodes and mesh members, each of which mesh members extends from one of which nodes to another, each of which nodes connects at least three of which mesh members to each other, and each node carries one or more of which bristle or tufts of which bristle. 【0277】 According to further embodiments of the first and / or second and / or third and / or fourth aspects of the present invention in Chapter 3, the meshwork may lie within a notch in the recess wall, or be embedded in the material of the recess wall, or be bonded or glued to the recess wall, or be positioned within a pressure chamber, overlapping with a hole in the recess wall, with the bristle tufts extending outward from the recess wall through the hole. 【0278】 According to further embodiments of the first and / or second and / or third and / or fourth aspects of the present invention of Chapter 3, each mesh member has a longitudinal direction defined by a virtual straight line extending between two of the nodes, with each mesh member extending between the nodes; the mesh member can be stretchable in its longitudinal direction, or at least a portion of the mesh member is stretchable in its longitudinal direction. The stretchability of the mesh member allows the mesh to follow deformations of the recessed wall, such as expansion and contraction, or local changes in the shape of the recessed wall during increasing and decreasing pressure. The stretchable mesh member can be elastically stretchable and / or can have a zigzag structure configured to provide the stretchability when viewed in the longitudinal direction of each mesh member. 【0279】 According to further embodiments of the first and / or second and / or third and / or fourth aspects of the present invention in Chapter 3, a mesh member or at least a portion of a mesh member may be configured to break when a predetermined force (such as a stretching force) acting on each mesh member is exceeded. The breakability of the mesh member allows the mesh to follow deformations of the recess wall, such as stretching or local changes in the shape of the recess wall during increasing and decreasing pressure. Additionally, the breakability of the mesh member allows the nodes of the mesh to remain attached to the recess wall while the mesh is still a single unit during the manufacturing of the mouthpiece and during the subsequent breaking of these mesh members (for example, by excessively increasing the pressure in the pressure chamber during or at the end of mouthpiece production), and during use, the nodes move independently of each other along with the movement of the recess wall resulting from increasing and decreasing pressure. 【0280】 According to further embodiments of the first and / or second and / or third and / or fourth aspects of the present invention in Chapter 3, at least one recess, viewed in its curved longitudinal direction, - Dental location in the range from the central incisors to the first molars; and / or, - Dental location in the range from the central incisors to the second molars; and / or, - Dental location in the range from the second premolar on the right side to the second premolar on the left side; and / or, - Dental location in the range from the right first molar to the left first molar; and / or, - Dental position in the range from the second molar on the right side to the second molar on the left side. It can be configured to include 【0281】 The curved longitudinal direction of the recess defines the curved longitudinal axis, which is the length of the longitudinal axis of the recess (or recess wall). - A distance at least equal to the distance from the central incisor to the first molar; and / or, - A distance at least equal to the distance from the central incisor to the second molar; and / or, - A distance at least equal to the distance from the second premolar on the right side to the second premolar on the left side; and / or, - A distance at least equal to the distance from the right first molar to the left first molar; and / or, - A distance at least equal to the distance from the second molar on the right side to the second molar on the left side. It means that it extends to that extent. 【0282】 Furthermore, the curved length axis can have a shape similar to, or at least a part of, the shape of the human dental arch. 【0283】 According to further embodiments of the first and / or second and / or third and / or fourth aspects of the present invention in Chapter 3, the bristle may be fixed to the recess wall at its end, which is attached to the recess wall. 【0284】 According to further embodiments of the first and / or second and / or third and / or fourth aspects of the present invention in Chapter 3, the recessed wall may be lined with at least five bristles per cm². For example, the recessed wall may be lined with 40 to 200 bristles per cm², for example, in the case of elastomer bristles, or with 1,000 to 6,000 bristles per cm², for example, in the case of nylon bristles. 【0285】 According to further embodiments of the first and / or second and / or third and / or fourth aspects of the present invention of Chapter 3, the recess wall is U-shaped in the transverse direction with respect to the longitudinal direction, coinciding with the U-shaped cross section of each recess, the central axis is defined as the mirror axis of the U-shape, and the U-shape of the recess defines two legs extending in the direction of the central axis, the legs may provide or be lined with bristles extending at angles in the range of 0 to 90 degrees with respect to the central axis, for example, in the range of 30 to 60 degrees. When the bristles extend at such angles, they point toward the gums, so to speak, in their natural position. When the pressure in the pressure chamber is increased, the recess wall is pressed toward the dental position, resulting in the tips of the bristles being pressed toward the gums, which contributes to the brushing action. For example, the free end of the leg may be provided with a bristle that extends at an angle in the range of 45 to 90 degrees with respect to the central axis, for example, in the range of 40 to 70 degrees with respect to the central axis. 【0286】 According to further embodiments of the first and / or second and / or third and / or fourth aspects of the present invention in Chapter 3, the recessed wall can be elastically deformable. 【0287】 [Brief explanation of the drawings in Chapter 3] The present invention in Chapter 3 will be further explained with reference to Figures 27 to 45. 【0288】 [Figure 27] This figure shows the dental position and the system of three orthogonal axes that define the dental arch, along with the lower dental arch. [Figure 28] This is a perspective view of a mouthpiece according to the first embodiment of the first aspect of the present invention in Chapter 3. [Figure 29a] This figure schematically shows a partial cross-sectional view of a second embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by arrow XXVIII-XXVIII in Figure 28. [Figure 29b] This figure schematically shows a partial cross-sectional view of a second embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by arrow XXVIII-XXVIII in Figure 28. [Figure 29c] This figure schematically shows a partial cross-sectional view of a second embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by arrow XXVIII-XXVIII in Figure 28. [Figure 30] This figure schematically shows a top view of a third embodiment of the mouthpiece according to the first aspect of the present invention as described in Chapter 3. [Figure 31a] This figure schematically shows a partial cross-sectional view of a third embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by the arrow XXX-XXX in Figure 30. [Figure 31b] This figure schematically shows a partial cross-sectional view of a third embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by the arrow XXX-XXX in Figure 30. [Figure 31c] This figure schematically shows a partial cross-sectional view of a third embodiment of the mouthpiece according to the first aspect of the present invention in Chapter 3, in each of its different operating states, and the cross-sectional view corresponds to the cross-section indicated by the arrow XXX-XXX in Figure 30. [Figure 32a] This figure illustrates the explanation of the second aspect of the present invention in Chapter 3, and the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 32b] This figure illustrates the explanation of the second aspect of the present invention in Chapter 3, and the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 32c] This figure illustrates the explanation of the second aspect of the present invention in Chapter 3, and the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 32d] This figure illustrates the explanation of the second aspect of the present invention in Chapter 3, and the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 33a] This figure illustrates a recessed wall that is not locally deformable. [Figure 33b] This figure illustrates a recessed wall that is not locally deformable. [Figure 34a] This figure provides a further explanation of the possibility of local deformation of the recessed wall of the mouthpiece according to the first embodiment of the present invention in Chapter 3. [Figure 34b] This figure provides a further explanation of the possibility of local deformation of the recessed wall of the mouthpiece according to the first embodiment of the present invention in Chapter 3. [Figure 35] This figure provides another further explanation of the possibility of local deformation of the recessed wall of the mouthpiece according to the first aspect of the present invention in Chapter 3. [Figure 36a] This figure schematically shows a partial cross-sectional view of the first embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of its different operating states. [Figure 36b] This figure schematically shows a partial cross-sectional view of the first embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of its different operating states. [Figure 36c] This figure schematically shows a partial cross-sectional view of the first embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of its different operating states. [Figure 37a] This figure schematically shows a partial cross-sectional view of the second embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of its different operating states. [Figure 37b] This figure schematically shows a partial cross-sectional view of the second embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of its different operating states. [Figure 37c] This figure schematically shows a partial cross-sectional view of the second embodiment of the mouthpiece according to the third aspect of the present invention in Chapter 3, in each of its different operating states. [Figure 38] This figure schematically shows the mesh structure according to the first embodiment of the third aspect of the present invention in Chapter 3. [Figure 39a] This figure schematically shows a mesh structure according to the second embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 39b] This figure schematically shows a mesh structure according to the second embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 40a] This figure schematically shows a mesh structure according to the third embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 40b] This figure schematically shows a mesh structure according to the third embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 41a] This figure schematically shows a mesh structure according to the fourth embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 41b] This figure schematically shows a mesh structure according to the fourth embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 42a] This figure schematically shows a mesh structure according to the fifth embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 42b] This figure schematically shows a mesh structure according to the fifth embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 43a] This figure schematically shows a mesh structure according to the sixth embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 43b] This figure schematically shows a mesh structure according to the sixth embodiment of the fourth aspect of the present invention in Chapter 3. [Figure 44] This figure schematically shows details of the flexible recessed wall. [Figure 45] This figure schematically shows the dental cleaning device according to the present invention according to Chapter 3, including the mouthpiece according to the present invention. 【0289】 [Detailed explanation of the diagram in Chapter 3] Figure 27 shows a very schematic perspective view of a portion of the upper dental arch 601 with dental positions 602–614. Each dental position is indicated by a vertical dashed line. Each dental position includes teeth that are typically named according to a nomenclature known to the dentist. Using this nomenclature: - Dental position 602 is the position of the left "second molar" as shown in Figure 27; - Dental position 603 is the position of the left "first molar," which is missing in Figure 27; - Dental position 604 is the position of the left "second premolar" as shown in Figure 27; - Dental position 605 is the position of the left "first premolar" as shown in Figure 27; - Dental position 606 is the position of the left "canine tooth" as shown in Figure 27; - Dental position 607 is the position of the left "lateral incisor," which is missing in Figure 27; - Dental position 608 is the position of the left central incisor as shown in Figure 27; - Dental position 609 is the position of the right central incisor as shown in Figure 27; - Dental position 610 is the position of the right lateral incisor as shown in Figure 27; - Dental position 611 is the position of the right canine as shown in Figure 27; - Dental position 612 is the position of the right "first premolar" as shown in Figure 27; - Dental position 613 is the position of the right "second premolar" as shown in Figure 27; - Dental position 614 is the position of the right "first molar" as shown in Figure 27; In Figure 27, the dental location of the right "second molar" is not shown, nor are the dental locations of the right and left "third molars" (also called wisdom teeth). Similarly, the mandible has a similar number of dental locations, which are similarly named according to the aforementioned nomenclature. 【0290】 Reference numeral 615 indicates the lingual side of the dental position arch. The lingual side 615 is the medial side of the dental position arch, and the medial side faces the tongue. Reference numeral 616 indicates the facial side of the dental position arch. The facial side 616 is the lateral side of the dental position arch, and the lateral side faces the face, such as the cheeks and lips. 【0291】 The mouthpiece according to the present invention in Chapter 3 is configured to brush multiple dental positions simultaneously. If teeth are present, the teeth at each dental position will be brushed. Due to the local deformability of the recessed wall according to the present invention in Chapter 3, the remaining portion of the dental position (such as the gums) will be brushed if there is a possibility of tooth loss, and the teeth adjacent to the missing tooth will be additionally brushed by the bristle intended for the missing tooth location. 【0292】 Figure 27 further illustrates a system of three mutually orthogonal axes, including the x-axis, y-axis, and z-axis. The z-axis is a curved axis following the contour of the dental arch 601. The x-axis and y-axis are perpendicular to each other and define the xy-plane, which is essentially flat and perpendicular to the dental arch 601; that is, each xy-plane intersecting at a given location on the z-axis is perpendicular to the curved z-axis at that location. The z-axis defines the curved longitudinal direction. The z-axis and y-axis define the curved zy-plane, which, when viewed along the z-axis, has an arch shape similar to the shape of the arch at the dental position. Furthermore, the z-axis and x-axis define the zx-plane. 【0293】 Figure 28 schematically shows a perspective view of the mouthpiece 620 according to the present invention as described in Chapter 3. The mouthpiece 620 includes a body portion 621 provided with a first recess 622. This first recess 622 has a curved longitudinal direction when viewed along the z-axis in Figure 27 and has a U-shaped cross-section when viewed in the xy-plane in Figure 27. The first recess 622 is bounded by a recess wall 623, which is U-shaped in the xy-plane. The recess wall 623 is lined with a plurality of bristle 624, each having one end attached to the recess wall 623 (called a root portion 649) and extending from the recess wall 623 into the first recess 622. 【0294】 Reference numeral 626 indicates a nipple, which is configured to connect the mouthpiece to the pumping and / or suction device. The mouthpiece 620 further has a right half 627 and a left half 628, which these halves come together in what is called the nipple 626. 【0295】 Reference numeral 625 indicates a curved dividing line, which defines a mirror plane parallel to the xz plane as defined in Figure 27. The mouthpiece shown in Figure 28 is, so to speak, mirror symmetric with respect to this mirror plane, meaning that a second recess (not visible in Figure 28) exists opposite the first recess 622, and this second recess is also lined with bristle. However, this second recess is visible in Figure 29, where it is similarly indicated by reference numeral 622. It should be noted that because the upper and lower arches (teeth) of the dental position have different shapes, the first recess can have a different shape from the second recess. 【0296】 The recess 622 is configured to encompass the entire dental arch from the dental position of the right third molar or second molar to the dental position of the left third molar or second molar, respectively. The recess 622 may also be configured to encompass a portion of the arch of dental positions, which may include at least five dental positions, for example, from the dental position of the central incisor to the dental position of the second premolar, or from the dental position of the first molar or the dental position of the second molar. 【0297】 Figure 29 shows a cross-section of the right-hand component of the second embodiment of the mouthpiece 700 according to the present invention in Chapter 3, indicated by arrow XXVIII in Figure 28, under different pressure conditions. In Figure 29, the same reference numerals are used with respect to similar components, as in Figure 28. 【0298】 The mouthpiece in Figure 28 and the mouthpiece in Figure 29 can be essentially the same, with Figure 28 showing a perspective view and Figure 29 showing a section XXVIII-XXVIII of the mouthpiece in Figure 28. The main difference, then, lies in the bristle. In Figure 28, the bristle 624 is relatively thick and can be fabricated as a single piece with the recess wall 623, while in Figure 29, the bristle is provided as a tuft 629 of a relatively thin bristle 624. Each tuft 629 can have a base 636, which supports the bristle 624 at its root 649 and is attached to the recess wall. 【0299】 As shown in Figure 29, the mouthpiece 700 has a body 621, which has a first recess 622 on its upper side and a second recess 622 on its lower side. Both recesses 622 are bounded by a flexible recess wall 623. In a cross section parallel to the xy plane as defined in Figure 27, the recess wall 623 is U-shaped and has a recess wall base 634 and two recess wall legs 633, the two recess wall legs 633 extending from the recess base wall. The recess wall 623 is covered by a bristle tuft 629. 【0300】 Inside the main body is a pressure chamber 635, which can be filled with a fluid via a nipple 626 (Figure 28). The fluid can be a gas such as air or a liquid such as water. In an embodiment as shown in Figure 29, the mouthpiece has one pressure chamber. However, it should be noted that the mouthpiece can include multiple pressure chambers, such as five pressure chambers as shown in Figures 30 and 31, or any other number of pressure chambers. Unpublished Patent Document 3 shows examples of other numbers of pressure chambers in Figures 4, 5, 7, 9, and 10, all of which are within the scope of the present invention in Chapter 3. In the case of multiple pressure chambers, all pressure chambers or groups of pressure chambers can be fluidly connected to each other, as described in Unpublished Patent Document 3, according to the present invention in Chapter 3. 【0301】 As shown in Figure 29, the mouthpiece may include an internal support structure made of a material rigid to the material of the recess wall 623. This support structure may include a lingual plate 630 and a facial plate 632, both of which extend along (for example, parallel to) the curved zy-plane defined in Figure 27, and consequently have a U-shape when viewed along the z-axis. To maintain the lingual plate 630 and the facial plate 632 at a predetermined distance from each other, the support structure may include one or more spacers 631. These one or more spacers 631 may be, for example, multiple bars or wires or a single plate, which may extend essentially parallel to the zx-plane as defined in Figure 27. In the case of a single plate as a spacer, this plate may divide the pressure chamber 635 into two pressure chambers (an upper chamber and a lower chamber). These two pressure chambers may be in fluid communication with each other through one or more through-holes in the plate. In the case of large through holes and / or multiple through holes, two pressure chambers can effectively be one single pressure chamber. 【0302】 Figures 29a, 29b, and 29c schematically show cross-sectional views of the mouthpiece 700 in its respective different operating states. These cross-sectional views can be approximately the same across the entire length axis Z of the dental arch, as defined in Figure 27. 【0303】 A single pressure chamber 635 includes a first flexible recess wall 623 defining the boundary of a first recess 622 (the upper one in Figure 29) and a second flexible recess wall 623 defining the boundary of a second recess 622 (the lower one in Figure 29). The first and second recess walls are deformable, in particular, by increasing or decreasing the pressure in the pressure chamber 635. The flexible recess wall 623 can be made from an elastic material, such as rubber. Alternatively, the flexible recess wall 623 can be made from an inelastic material. The material of the flexible recess wall 623 can maintain a predetermined shape when there is virtually no pressure difference or a low pressure difference across the inner and outer sides of the flexible recess wall 623. 【0304】 The mouthpiece 700 is configured such that the tufts 629 of the bristle 624 engage with the tooth surfaces of the dental arch, or, in the case of one or more dental positions where teeth may be missing, the tufts 629 of the bristle 624 engage with the gums at each dental position when the pressure in the pressure chamber 635 is increased. In particular, if there may be missing teeth at a given dental position, the tufts 629 of the bristle at the free end of the recessed wall leg 633 will engage with the gums at the empty dental position. 【0305】 When viewed along the longitudinal direction Z of the dental arch (as defined in Figure 27), the tufts 629 of the bristle 624 can be arranged at approximately the same density when viewed in the cross-sections shown in Figures 29a, 29b, and 29c. 【0306】 Figure 29a illustrates the first operating state (also called the intermediate state) of the mouthpiece 700. In the intermediate state, the pressure inside the pressure chamber 635 can be equal to, lower than, or higher than atmospheric pressure. 【0307】 Figure 29b illustrates a second operating state of the mouthpiece 700 when the pressure chamber 635 is under increased pressure, for example, by supplying fluid to the pressure chamber 635 or by increasing the amount of fluid in the pressure chamber 635. As can be seen in Figure 29b, as a result of increasing the pressure, the recess wall 623 is so to speak compacted, narrowing the recess 622 (compared to Figure 29a), thereby allowing the bristle 624 (in particular its free end) to firmly engage with the tooth surface and / or be deformed in contact with the tooth surface. 【0308】 Figure 29c illustrates a third operating state of the mouthpiece 700 when the pressure in the pressure chamber 635 is reduced, for example, by discharging fluid from the pressure chamber 635 or by reducing the amount of fluid in the pressure chamber 635. As can be seen in Figure 29c, as a result of reducing the pressure, the flexible recess wall 623 expands, so to speak, to enlarge the recess 622 compared to Figure 29a, thereby preventing the bristle 624 (in particular its free end) from firmly engaging with (or not engaging with at all with) the tooth surface and / or from contacting and deforming the tooth surface. 【0309】 The most effective brushing action of the mouthpiece can be obtained by returning to the first operating state through appropriate cycles of increasing and decreasing the pressure in the pressure chamber 635, from the first operating state to the second operating state, then from the second operating state to the first operating state, and then from the first operating state to the third operating state, and thereafter by repeating such cycles. The bristle 624 attached to the bottom of the recessed wall 634 generally performs upward and downward motion during such cycles, while the bristle 624 at the leg of the recessed wall 633 generally performs lateral motion back and forth in the x-axis direction as defined in Figure 27 during such cycles. As the pressure is reciprocally increased and decreased, the recess 622 alternately narrows and widens, causing the bristle 624 at the base of the recess wall to also be subjected to pivoting back and forth around the z-axis as defined in Figure 27, resulting in a sweeping movement of the bristle in the direction of the y-axis as defined in Figure 27. 【0310】 It should be noted that in the operating state of Figure 29c (decreased pressure state), the pressure inside the pressure chamber 635 can be a vacuum, i.e., a pressure lower than atmospheric pressure. When in the operating state of Figure 29c (increased pressure state), the pressure inside the vacuum chamber is a vacuum (e.g., 0.7 bar), and the pressure inside the pressure chamber 635 in the operating state of Figure 29b can be a vacuum, atmospheric pressure, or a pressure higher than atmospheric pressure. Additionally, it should be noted that in the operating states of Figures 29b and 29c, the pressure inside the pressure chamber can be higher than atmospheric pressure in both cases, or in the operating state of Figure 29b, the pressure inside the pressure chamber can be approximately atmospheric pressure, while in the operating state of Figure 29c, the pressure inside the pressure chamber can be higher than atmospheric pressure. 【0311】 As merely an example to provide some indication of dimensions, and referring to Figure 27, for adults, the width of the tooth elements in the X direction varies between approximately 2 mm and 12 mm, depending on the dental position. Taking into account the desire to keep the mouthpiece as small as possible, the internal width of the U-shaped recess wall in the X direction should be kept as small as possible, and can be approximately 0 mm to 4 mm wider than the width of each tooth. As an example to provide some indication of dimensions, the internal width of the U-shaped recess wall can range from 0 mm to 20 mm when viewed in the X direction in Figure 27, and can range, for example, from 2 mm to 12 mm. The bristle can be up to 6 mm in length. In the example, the bristle is 3 mm to 4 mm in length, which means that there is no gap remaining between the bristles extending from the opposing recess wall legs 633, or a limited amount of gap of approximately 2 mm to 4 mm remains. In Figure 29, these gaps are shown in an exaggerated manner. Furthermore, as an example to provide some indication of dimensions, the U-shape of the recessed wall can have an internal height ranging from 3 mm to 20 mm when viewed in the Y direction in Figure 27, for example, from 5 mm to 10 mm. These internal width and internal height measurements are given for adults. These measurements may differ for children or animals. 【0312】 Figure 30 schematically shows a top view of a third embodiment 710 of the mouthpiece according to the present invention as described in Chapter 3. Figures 31a, 31b, and 31c schematically show cross-sectional views of the mouthpiece 710 in its respective different operating states, indicated by arrows XXX-XXX in Figure 30. These cross-sectional views can be substantially the same along the entire length axis Z of the dental arch as defined in Figure 27. 【0313】 Considering that the mouthpiece 710 in Figures 30-31 is very similar to the mouthpiece 700 in Figure 29, the same reference numerals used in relation to Figures 28-29 are used for the same or similar parts of the mouthpiece 710. 【0314】 There are essentially two differences between the mouthpiece 700 in Figure 29 and the mouthpiece 710 in Figures 30-31. Each of these differences can be applied separately to the mouthpieces in Figures 28 and / or 29 without applying the other difference. 【0315】 The first difference is that the mouthpiece in Figures 30–31 has five pressure chambers 635a, 635b, 635c, 635d, and 635e. In Figure 30, pressure chambers 635a, 635c, and 635e are shown by shaded gray areas. As can also be seen in Figure 30, nipple 626 has a channel 637a for providing fluid communication with an external pressure source. This channel 637a flows into pressure chambers 635c and 635a (not shown in Figure 30). Channel 637b connects pressure chambers 635c and 635a to pressure chamber 635e, providing fluid communication between these chambers. Channel 637c connects pressure chamber 635e to pressure chambers 635a and 635b, providing fluid communication between these chambers. Overall, all pressure chambers 635a, 635b, 635c, 635d, and 635e are in fluid communication with one another, so that they can act as a single pressure chamber, like pressure chamber 635 of mouthpiece 700. The mouthpiece 710 can also have three operating states, or two if one is omitted, as described in relation to Figures 29a, 29b, and 29c. The descriptions of the operating states shown in Figures 31a, 31b, and 31c are referenced in the descriptions of Figures 29a, 29b, and 29c. 【0316】 The second difference is that the mouthpieces in Figures 30 and 31 have a slightly different support structure. The lingual plate 630 and facial plate 632 of mouthpiece 710 are located outside the main body 621, instead of being embedded inside the main body as in the case of mouthpiece 700. Also, both the lingual plate 630 and facial plate 632 of mouthpiece 710 extend along the curved zy-plane defined in Figure 27, and consequently have a U-shape when viewed along the z-axis. In the embodiments of Figures 30 and 31, the lingual plate 630 and facial plate 632 may be maintained at a predetermined distance from each other by additional spacers (not shown), although the recessed wall bottom 634 may also serve as such a spacer. 【0317】 Referring to Figures 32 to 35, the possibility of local deformation of the recess wall according to the first aspect of the present invention in Chapter 3 will be explained here, and the second aspect of the present invention in Chapter 3 will also be explained. 【0318】 Up to this point, the overall deformability of the recessed wall 623 has been described with reference to Figures 27 to 31, and this overall deformability occurs when at least one pressure chamber 635 is operated with the bristle 624 or tuft 629 with bristle 624 mounted on top of the recessed wall 623. However, according to the first aspect of the present invention in Chapter 3, the recessed wall 623 is further configured to have local deformability. This local deformability of the recessed wall 623 will be described here with reference to Figures 32a, 32b, 32c, and 32d. 【0319】 Figures 32a and 32b are essentially identical. The difference is that in Figure 32b, only one tuft 629 is shown for illustrative purposes, while in Figure 32a, multiple tufts 629 are shown. 【0320】 Figures 32a and 32b schematically show the dental arch 601 and the flexible recessed wall leg 633 of the flexible recessed wall 623 located on the facial side of the dental arch 601. This flexible recessed wall leg 633 is locally deformable. 【0321】 Since Figures 32a and 32b are for illustrative purposes only, the remaining recessed wall legs 633 extending along the facial side of the dental arch 601, the recessed wall legs 633 extending along the lingual side of the dental arch 601, and the recessed wall base 634 extending along the occlusal surface and optionally along the incisal edge are not shown. Furthermore, all of these unillustrated components of the recessed wall 623 may also be configured to have local deformability. 【0322】 Figures 32a and 32b illustrate the local deformability of the flexible recess wall 623, particularly the local deformability of the recess wall leg 633, resulting from increasing and decreasing pressure within the pressure chamber. As can be seen, the recess wall leg 633 has an irregular shape when viewed along the z-axis, which follows the irregularity of the dental position of the dental arch 601. For illustrative purposes, the irregular shape of the recess wall leg 633 closely matches the irregular shape of the dental arch 601 adjacent to the recess wall leg 633. As will become apparent, the irregular shape of the recess wall leg 633 may be less distinct than the irregular shape of the dental arch 601. 【0323】 Figures 32a and 32b show the recessed wall leg 633 under increased pressure conditions. As shown in Figures 32a and 32b, the primary direction of pressure on the recessed wall leg 633 is in the x-axis direction. When the pressure is decreased, the recessed wall leg 633 moves away from the dental arch 601, reducing the pressure exerted on the teeth 640 by the tuft 629. When the pressure on the recessed wall leg 633 is increased again, the recessed wall leg 633 moves toward the dental arch 601. This alternating movement in the x-axis direction is the first dimension of brushing movement realized by the mouthpiece according to the present invention in Chapter 3. 【0324】 When the pressure on the flexible recessed wall leg 633 is reduced, the flexible recessed wall leg 633 not only moves away from the dental arch 601, but also, due to its local deformability, tends to revert to a less distinct, irregular shape under reduced pressure conditions. This less distinct, irregular shape can be a continuously curved shape parallel to the z-axis, or it can still be a shape with relief, but with less relief than under increased pressure conditions, provided that the flexible wall component moves sufficiently away from the dental arch. This local change in the shape of the recessed wall 623 / recessed wall leg 633 causes the tuft 629, which is mounted in or near that location, to rotate around the y-axis, resulting in sweeping in the z-direction along the facial surface of the tooth. When the pressure on the flexible recessed wall leg 633 is increased, the tuft 629 tends to return to the position shown in Figures 32a and 32b, resulting in sweeping in the opposite z-direction along the facial surface of the tooth. This alternating sweeping movement in the z-axis direction (indicated by the bidirectional arrows 641 in Figures 32a and 32b) is due to the local deformability of the flexible wall component and is a second dimension of brushing movement realized by the mouthpiece according to the present invention in Chapter 3. 【0325】 The sweeping movement 641 in the z-axis direction around the y-axis is caused by local irregularities in the dental arch 601 in the z-axis direction, and local deformation of the flexible wall component (at the location of the local irregularity) when the pressure is increased and decreased. 【0326】 As schematically shown in Figure 32c, the irregularity of the dental arch 601 in the y-axis direction, and the local deformability of the flexible recessed wall leg 633 of the flexible recessed wall 623, similarly cause the tuft 629 to sweep in the y-direction around the z-axis when the pressure in the pressure chamber 635 is increased and decreased. This alternating sweeping movement in the y-axis direction and around the z-axis (this sweep is indicated by the bidirectional arrow 642 in Figure 32c) is due to the local deformability of the flexible wall component and is a third dimension of brushing movement realized by the mouthpiece according to the present invention in Chapter 3. 【0327】 Referring to Figure 32d, the local deformability of the recess wall, all together, results in at least an additional two-dimensional brushing action as shown in Figure 32d by the cone 643. This additional two-dimensional brushing action is added to the brushing action already caused by the pulsating pressure. The main brushing action caused by the pulsating pressure is shown in Figure 32d by the bidirectional arrow 644 and has been described above in relation to Figures 28-31. Since arrow 644 represents a third dimension, the overall brushing action at location L in Figure 32d is therefore a three-dimensional brushing action: the bristle reciprocates and pivots around the y-axis, the bristle reciprocates and pivots around the z-axis, and the bristle reciprocates and translates along the x-axis. As will become clear, the local deformability of the recessed wall leg portion 633 on the lingual side, and the local deformability of the recessed wall base portion 634, similarly result in an additional two-dimensional brushing action. 【0328】 More generally, and looking at the location of the root of a random bristle 649, the additional two-dimensional brushing action includes a first reciprocating and pivoting movement of the bristle, and a second reciprocating and pivoting movement of the bristle, the two reciprocating and pivoting movements of which are added to a third reciprocating translational movement caused by pressure pulsations in the pressure chamber. Referring to a system of orthogonal axes as shown in Figure 27, and looking at the location of the root of a bristle, the root of each random bristle lies in an xy-plane perpendicular to the curved z-axis. If we call the xy-plane at the location of the root of the bristle the local xy-plane, the reciprocating translational movement at this location of the root of the bristle lies in this local xy-plane and is therefore perpendicular to the z-axis. Considering that the recessed wall has an essentially U-shape in this local xy-plane, corresponding to the U-shaped cross-section of the recess, this reciprocating translational movement is also approximately perpendicular to the U-shape of the recessed wall in this local xy-plane. The first reciprocating pivotal movement is around the z-axis at location L of the base of each bristle, that is, around a first pivot axis perpendicular to the local xy-plane. The second reciprocating pivotal movement is around a second pivot axis, which is perpendicular to the first pivot axis (or z-axis) and also perpendicular to the third reciprocating translational movement. Further generalizing by omitting the bristle, the local deformability of the recess wall is such that, when reciprocating the pressure in the at least one pressure chamber is increased and decreased, and when encompassing the plurality of dental positions in the recess, each location of the recess wall is subjected to a first reciprocating pivotal movement around a first pivot axis, a second reciprocating pivotal movement around a second pivot axis, and a reciprocating translational movement along a translation axis, the first pivot axis, the second pivot axis, and the translation axis being perpendicular to each other. 【0329】 It should be noted that, in addition to the first, second, and third reciprocating movements discussed above, the recessed wall can also enable fourth, fifth, and sixth reciprocating movements that can further contribute to the brushing action. The fourth reciprocating movement is a reciprocating translational movement in the z-axis direction at the location of the bristle root, which can result from, for example, the elasticity of the recessed wall in the z-axis direction and adds a fourth dimension to the brushing movement of the bristle. The fifth reciprocating movement is a reciprocating translational movement in the y-axis direction at the location of the bristle root, which can result from, for example, the elasticity of the recessed wall in the y-axis direction or the translation of the recessed wall in the y-direction (see, for example, Figures 36b and 37b) and adds a fifth dimension to the brushing movement of the bristle. The sixth reciprocal movement is a reciprocal rotational movement around the x-axis at the location of the bristle's root, which can result from, for example, a local rotation of the concave wall around the x-axis, adding a sixth dimension to the bristle's brushing movement. 【0330】 Referring to Figures 33 and 34, it will become clear that the local deformability of the recessed wall also results in improved interdental brushing and more regular brushing pressure acting on the dental position. Both Figures 33 and 34 show, for illustrative purposes, a portion of the recessed wall leg 633 acting on the sides of three teeth 640 (with interdental space 638 present between them). Figure 33 shows the situation with the recessed wall leg 633 configured without local deformability, with Figure 33a showing a reduced pressure state and Figure 33b showing an increased pressure state. On the other hand, Figure 34 shows the situation with the recessed wall leg 633 configured to have local deformability according to a first aspect of the present invention in Chapter 3, with Figure 34a showing a reduced pressure state and Figure 34b showing an increased pressure state. 【0331】 Comparing the reduced pressure state in Figure 33a with the increased pressure state in Figure 33b, it can be understood that the extent to which the intertooth space 638 is reached by the bristle 624 is determined by the length of the bristle and the distance d from the recess wall leg 633 to the side of the tooth 640. The minimum value of distance d may be smaller than that shown in Figure 33b. However, due to the fact that the recess wall leg 633 in Figure 33 is not locally deformable, the recess wall leg 633 remains flat as shown in Figure 33b, resulting in the distance e of the recess wall leg 633 to the deepest point of the intertooth recess being larger compared to the situation in Figures 34a and 34b. The minimum values ​​with respect to distances d and e are reached when the bent or straight bristle 624 in areas 645a, 645b, and 645c (they are on the opposite side of the tooth 640 and not on the opposite side of the interdental space 638) prevent the recessed wall leg 633 from moving further toward the tooth 640. Now, referring to Figure 34, it will be understood that due to the local deformation of the recessed wall leg 633 at location 639 opposite the interd...

Claims

[Claim 1] A mouthpiece for brushing multiple dental positions simultaneously, comprising a body portion provided with at least one recess; The at least one recess has a curved longitudinal direction and a U-shaped cross-section transverse to the longitudinal direction, and is configured to encompass a plurality of at least five dental positions when viewed in the curved longitudinal direction; The main body includes, for each of the recesses, a flexible recess wall that defines the boundary of each recess. The mouthpiece further includes a meshwork fixed to the recess wall, the meshwork being formed of nodes and mesh members, each of which extends from one node to another, each of which connects at least three of the mesh members to each other, each node bearing one or more bristle, the bristle optionally arranged in a bristle tuft, the recess wall being lined by the plurality of bristles, each of which has one end attached to the recess wall and extends from the recess wall into the recess; The main body is provided with at least one pressure chamber configured to contain a fluid under pressure; In a mouthpiece, the main body is configured to deform the recessed wall by reciprocating the pressure in at least one pressure chamber between a decreased pressure state and an increased pressure state, A mouthpiece characterized in that the recessed wall is configured to have local deformability, and the shape of the recessed wall changes locally when the pressure in the at least one pressure chamber is reciprocally increased and decreased, wherein in the increased pressure state, the shape of the recessed wall is locally adjusted to the local shape of the dental position enclosed by the recessed wall, while in the decreased pressure state, the shape of the recessed wall is not locally adjusted to the local shape of the dental position enclosed by the recessed wall as much as in the increased pressure state. [Claim 2] The mouthpiece according to claim 1, wherein, viewed along the longitudinal direction along the lingual and facial sides of the dental position encompassed by the recessed wall, the recessed wall has less relief in the reduced pressure state than in the increased pressure state. [Claim 3] The mouthpiece according to claim 1 or 2, wherein the local deformability of the recessed wall is configured such that the local change in the shape of the recessed wall between the increased pressure state and the decreased pressure state occurs in a pressure difference in the range of greater than 0 bar and up to 2 bar, the pressure difference being defined as the difference between the pressure in the pressure chamber in the increased pressure state and the pressure in the pressure chamber in the decreased pressure state. [Claim 4] The mouthpiece according to any one of claims 1 to 3, wherein, in the reduced pressure state, the pressure in the at least one pressure chamber is higher than the atmospheric pressure. [Claim 5] The mouthpiece according to any one of claims 1 to 4, wherein, in the increased pressure state, the pressure in the at least one pressure chamber is at most 2 bar relative to atmospheric pressure. [Claim 6] The mouthpiece according to any one of claims 1 to 5, wherein, in the increased pressure state, the pressure in the at least one pressure chamber is at most 0.3 bar relative to atmospheric pressure. [Claim 7] The mouthpiece according to any one of claims 1 to 6, wherein, in the reduced pressure state, the pressure in the at least one pressure chamber is lower than atmospheric pressure. [Claim 8] The mouthpiece according to any one of claims 1 to 6, wherein, in the reduced pressure state, the pressure in the at least one pressure chamber is in the range of -0.5 bar to +0.2 bar relative to atmospheric pressure. [Claim 9] The local deformability of the recess wall is such that when the pressure in the at least one pressure chamber is reciprocatedly increased and decreased, and when the plurality of dental positions are enclosed in the recess, each location of the recess wall is subjected to a first reciprocating pivot movement about a first pivot axis, a second reciprocating pivot movement about a second pivot axis, and a reciprocating translation movement along a translation axis, wherein the first pivot axis, the second pivot axis, and the translation axis are perpendicular to each other, the mouthpiece according to any one of claims 1 to 8. [Claim 10] The mouthpiece according to any one of claims 1 to 9, wherein each bristle is attached to the base of each bristle at each node of the meshwork fixed to the recess wall, and the local deformability of the recess wall is such that when the pressure in the at least one pressure chamber is reciprocatedly increased and decreased and when the plurality of dental positions are contained in the recess, the base of each bristle is subjected to a first reciprocating pivot movement around a first pivot axis, a second reciprocating pivot movement around a second pivot axis, and a reciprocating translation movement along a translation axis, the first pivot axis, the second pivot axis, and the translation axis are perpendicular to each other. [Claim 11] Each bristle is attached to the respective node of the meshwork, which is fixed to the recessed wall at the mounting point; At each mounting point, a local set of three mutually orthogonal axes is defined, the local set comprising the x-axis, y-axis, and z-axis, wherein the z-axis is a curved axis defined by the curved longitudinal direction of the recess, and the x-axis and y-axis define an xy-plane perpendicular to the z-axis; The local deformability of the recess wall is such that when the pressure in the at least one pressure chamber is reciprocally increased and decreased, and when the plurality of dental positions are enclosed within the recess, the mounting point is subjected to one or more movements from the group consisting of a first reciprocating pivot movement around a first pivot axis, a second reciprocating pivot movement around a second pivot axis, and a reciprocating translation movement along a translation axis; The mouthpiece according to any one of claims 1 to 10, wherein the first pivot axis is parallel to the z axis, and the second pivot axis and translation axis are in the xy plane and perpendicular to each other. [Claim 12] The mouthpiece (620) according to any one of claims 1 to 11, wherein the main body portion is provided with two recesses, and the openings of the U-shaped cross-sections of the two recesses are oriented in opposite directions to each other. [Claim 13] The recessed wall has a U-shape in the transverse direction with respect to the longitudinal direction, which coincides with the U-shaped cross-section of the recess; The U-shape of each recessed wall defines two recessed wall legs extending from the bottom of the recessed wall, each leg having a free end; The free ends of the two recessed wall legs are provided with end bristles supported on the nodes of the meshwork; The main body is, - When the pressure in the at least one pressure chamber is increased, the free ends of the two recessed wall legs are configured to shift from the inside of the recess to the outside of the recess. - When the pressure in the at least one pressure chamber is reduced, the upper ends of the two recessed wall legs are configured to shift from the outside of the recess to the inside of the recess. The mouthpiece according to any one of claims 1 to 12, wherein the end bristle is subjected to reciprocating swivel movement about an axis parallel to the longitudinal direction when the pressure in the at least one pressure chamber is reciprocatedly increased and decreased. [Claim 14] A method for operating a mouthpiece according to any one of claims 1 to 13, The pressure in at least one pressure chamber is reciprocally increased and decreased by a pressure difference in the range of greater than 0 bar and up to 2 bar, the pressure difference being defined as the pressure in the pressure chamber in the increased pressure state minus the pressure in the decreased pressure state; and / or, The pressure in the at least one pressure chamber is reduced reciprocally to a reduced pressure state with a pressure higher than atmospheric pressure, and increased to a pressure higher than the pressure in the reduced pressure state; and / or The pressure in the at least one pressure chamber is reciprocally increased to a pressure state that is at most 2 bar higher than atmospheric pressure, and then decreased to a pressure lower than the pressure in the increased pressure state; and / or The pressure in the at least one pressure chamber is reciprocally increased to a pressure state that is at most 0.3 bar higher than atmospheric pressure, and then decreased to a pressure lower than the pressure in the increased pressure state; and / or The pressure in the at least one pressure chamber is reciprocally reduced to a reduced pressure state with a pressure lower than atmospheric pressure, and increased to a pressure higher than the pressure in the reduced pressure state; and / or A method wherein the pressure in at least one pressure chamber is reciprocally reduced to a reduced pressure state in the range of -0.5 bar to +0.2 bar relative to atmospheric pressure, and increased to a pressure higher than the pressure in the reduced pressure state.

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