An orthodontic device and methods of manufacture

Abstract

An orthodontic device for the segmental distalization of a posterior jawbone area is disclosed. The device comprises a mesial element having a mesial base surface configured for attachment to a premolar or a canine, a projection for coupling with a traction element, and an arm. The arm comprises a transverse pivot at a distal end of the arm. The device further comprising a distal element having a distal base configured for attachment to a molar, and a distal cap, wherein the transverse pivot arranged between the distal base and the distal cap. Methods for assembly of orthodontic devices are also provided.

Description

An orthodontic device and methods of manufacture

[0001] The present application claims the benefit of US provisional patent application n° 63 / 446.191 filed on February 16th, 2024.FIELD

[0002] The present disclosure relates to an orthodontic device, and more particularly relates to an orthodontic device for segmental distalization of a posterior jawbone sector. The present disclosure further relates to methods of manufacture and assembly of such devices.BACKGROUND

[0003] Depending on a patient’s malocclusion, a variety of orthodontic treatments is available. In some of these treatments, extraction of teeth may be required in order to create space for the remaining teeth. In some treatments, a distalizing element may be used, possibly in combination with the extraction of one or more teeth.

[0004] A segment of teeth is herein defined as a group of neighbouring teeth, i.e. two or more neighbouring teeth. Distalization of the segment of teeth relates to moving a group of teeth together. In particular, in the present disclosure distalization refers moving a group of teeth in the distal direction of the mouth. The group of teeth may be located in the upper jawbone (maxilla) or in the lower jawbone (mandible).

[0005] A particular distalizing element is known from e.g. EP 1 433 435 and EP 1 649 824. These distalizers are especially adapted for the segmental distalization of the canine-to-molar posterior maxillary area. The distalizers of these documents comprise a mesial element which may be fixed by its base to an upper canine, and further comprises a distal element which may be fixed by its base to an upper molar, in particular the first molar.

[0006] The mesial element in these designs comprises both a base, and an arm that connects it to the distal element. The arm may be substantially arch shaped and may comprise a ball member at one of its ends. This ball member is received in a receptacle of the distal element that has a complementary shape to the ball member.

[0007] The mesial element may comprise a blunt projection that extends substantially forwards which may serve as a hooking element. In use, a bracket with a hook may be attached to a mandibular molar and an (orthodontic) rubber band may be suspended around this hook and the hooking element on the mesial element.

[0008] This way, a force pulling the maxillary canine backwards is provided. If the patient is wearing e.g. a splint (or another fixation device) that acts as a solid anchor and fixes the teeth of the mandible in position, it may be ensured that the teeth in the mandible do not move forwards, and that the maxillary canine is pulled backwards.

[0009] Due to the connection between the mesial element and the distal element of the distalizer, the maxillary molar may thus also be pushed backwards. At the same time, due to the shape of the arm in between the canine and the molar and due to the position of the distal element on the molar, a rotational force is also exerted upon the molar. This rotational force may result in a pivot about the palatal root of the maxillary molar. Also, a rotation in the distal direction of the molar (“uprighting”) may result. Thus a backwards force and a rotational force may be exerted upon the molar at the same time.

[0010] In order to avoid that the maxillary molar rotates too much in the distal direction (i.e. in this case, it would assume an orientation in which it is tilted backwards), the shape of the receptacle and the ball member are such that with a predetermined rotation of the ball member with respect to the upper molar, the ball member touches the inside of the receptacle and cannot rotate further. To this end, both the mesial element and distal element are mounted at the right height on the molar and canine and are mounted substantially straight along the locally defined mandible-maxilla (straight up-down) direction on the surface of the tooth. The arm is provided at a predefined angle with respect to the ball member. When both the canine and molar are actually straight, this angle will make sure that the ball member or the arm of the mesial element touches the border of the receptacle and cannot rotate further.

[0011] Similarly, the shape of the ball member and the border of the receptacle may be such that a rotation of the upper molar around its palatal root is limited. Once a predetermined rotation is reached, the arm may touch the border of the receptacle and the ball member is not able to rotate further.

[0012] It may thus be ensured that a distalization of the canine-molar segment may be combined with a proper (re)orientation of the set of teeth in the maxillary posterior region.

[0013] LIS2011 / 0244414 provides a further distalization device which has a reduced height, as compared to the devices described in EP 1 433 435 and EP 1 649 824. The distalization device of US 2011 / 0244414 consists of a single element coupled to a canine / premolar and amolar. The coupling involving a ball member and receptacle is not present in this device. This allows a height reduction, and makes it possible to use the device in treatments of many patients in the mandible, but limits the functionality of the distalization device, as the rotation of the mesial element with respect to the distal element and corresponding collision points of the ball member or arm and the receptacle are eliminated. These devices therefore have a limited ability to adjust the position of a molar both in “uprighting” and in torsion.

[0014] Another distalization device is known from WO 2018 / 219858. This prior art document discloses an orthodontic device for the segmental distalization of a posterior jawbone area comprising a mesial element including a projection for coupling with a traction element, and an arm wherein the arm comprises an elongate transverse pivot at a distal end of the arm. The elongate transverse pin is received in a receptable of a distal base. The elongate transverse pin is able to pivot with respect to the distal base and thus allows segmental distalization in combination with uprighting and rotation around the molar palatal root. An interior of the receptacle limits the pivotal movement of the elongate transverse pin. In an example, the elongate transverse pin is substantially condyle-shaped. These devices can provide effective segmental distalization and have a reduced height and thereby facilitate use particularly in the mandible of patients.

[0015] WO 2018 / 219858 describes a process for assembly of the distalization device, according to which the receptacle of the distal base is slightly enlarged with respect to the pin so that the pin can be introduced without deforming the pin. After introduction of the pin, the opening of the receptacle may be reduced, involving e.g. local deformation or deformation of the complete border. In particular, local deformation involving coining is a preferred example.

[0016] The present disclosure provides further improvement of distalization devices and methods of manufacture and assembly.SUMMARY

[0017] According to a first aspect, an orthodontic device for the segmental distalization of a posterior jawbone area is provided. The orthodontic device comprises a mesial element having a mesial base surface configured for attachment to a premolar or a canine, a projection for coupling with a traction element, and an arm. The arm comprises a transverse pivot at a distal end of the arm. The orthodontic device further comprises a distal element having a distal base configured for attachment to a molar, and a distal cap. The transverse pivot is arranged between the distal base and the distal cap.

[0018] In a further aspect, a method for assembling a distalization device is provided. The method comprises providing a mesial element having a mesial base surface configured for attachment to a premolar or a canine, a projection for coupling with a traction element, and an arm, wherein the arm comprises a pivot at a distal end of the arm. The method further comprises providing a distal base with a distal base surface configured for attachment to a molar and positioning the pivot on the distal base. The method then comprises placing a distal cap over the pivot so as to enclose the pivot between the distal base and the distal cap and joining the distal cap to the distal base.

[0019] The method according to this aspect may be used to assemble a distalization device in accordance with the first aspect.

[0020] In accordance with these aspects, an orthodontic device and method for assembly are provided which can ensure accurate and effective distalization. For accurate and secure distalization, it is important that the mesial element can pivot with respect to the distal element (or vice versa). The pivoting allows continued operation even if uprighting of the molar and / or rotation about the molar’s palatal root occurs.

[0021] At the same time, the ability to pivot is preferably limited to specific maximum rotations. I.e. the orthodontic device may be designed such that when a specific amount of rotation is reached, the distal and mesial element enter into contact, thereby limiting the rotation. These contact points are preferably precisely defined. The assembly process is such that the mesial and distal element can be precisely manufactured and the assembly process does not introduce any deformations to either element. The pivot is positioned on the distal base, and then is enclosed by placing the distal cap over the pivot. No deformation of either the distal element, the pivot or any other element occurs.

[0022] In a further aspect of the present disclosure, a method for assembling a distalization device is provided. The method comprises providing a mesial element having a mesial base surface configured for attachment to a premolar or a canine, a projection for coupling with a traction element, and an arm, wherein the arm comprises a pivot at a distal end of the arm. The method further comprises providing a distal base with a distal base surface configured for attachment to a molar and positioning the pivot on the distal base. The method then comprises additively manufacturing a distal cap over the pivot so as to enclose the pivot between the distal base and the distal cap and joining the distal cap to the distal base.

[0023] In yet a further aspect of the present disclosure, a method for assembling a distalization device is provided. The method comprises providing a mesial element having a mesial base surface configured for attachment to a premolar or a canine, a projection forcoupling with a traction element, and an arm, wherein the arm comprises a pivot at a distal end of the arm. The method further comprises providing a distal base with a distal base surface configured for attachment to a molar and having a receptacle for receiving the pivot. The method then comprises introducing the pivot with a first orientation into the receptable, and handling the pivot to assume a second orientation once inserted in the receptacle. The receptacle and pivot are shaped such that the pivot cannot be extracted from the receptacle when the pivot is in the second orientation.

[0024] In accordance with this aspect, a method of assembly is provided which allows introduction of the pivot only in one specific orientation, i.e. no mistakes can be made. After introduction, the pivot may be rotated or otherwise manoeuvred so as to assume a second orientation, in which it cannot be removed from the receptacle. In use, it is therefore not possible for the pivot to be dislocated from the receptacle.

[0025] In some examples, the transverse pivot has a mesial surface and a distal surface, wherein an interior shape of the distal cap is such that the transverse pivot can be rotated about the first axis over an angle between 1° and 45°, and wherein the rotation about the first axis is limited by the mesial and / or distal surface touching against an inside of the receptacle. That is, the interior shape of the distal cap is such that it permits the indicated range of rotation.

[0026] The transverse pivot according to this aspect may have a reduced height as compared to a ball member, and may thus be mounted also in the mandible of patients without bothering a patient, because contact with an inside of the cheek and the device or contact between a molar in the maxilla and the device can be avoided.

[0027] The transverse pivot having a mesial surface and a distal surface entering into contact with an inside of the receptacle to limit the rotation around the first axis provides the functionality of limiting uprighting of the molar.

[0028] In some examples, the transverse pivot can be rotated about the first axis over an angle between 5° and 20°, and specifically between 8° and 12°. I.e. the pivot and distal cap are such that the indicated range of rotation is permitted.

[0029] In some examples, the transverse pivot may be substantially cylindrical. In further examples, cross-sectional dimensions of the transverse pivot may reduce gradually from a central point of attachment to the arm towards both extremes of the pin. An aspect of the gradual reduction is that a smoothly increasing contact between the distal and mesial surfaces of the transverse pivot and the inside of the receptacle is provide as the transverse pivot rotates about the first axis.

[0030] In some examples, the transverse pivot may be substantially condyle-shaped, i.e. shaped as a rounded prominence that may be found at the end of a bone, e.g. shaped as the mandibular condyle. The transverse pivot can herewith mimic an articulation that may be found in the human body.

[0031] In some examples, the transverse pivot may have a longitudinal axis and the receptacle may be such that the transverse pivot can be rotated about the longitudinal axis over an angle between 0° and 60°, specifically between 15° and 45°. The degree of rotation allowed along the longitudinal axis may be limited by the arm colliding against an inside of the distal cap, and / or against the distal base. The degree of rotation allowed determines the rotation of the molar about its palatal root. Rotation around the first and the second axis, in combination with the reduced height of the device enables treatment of patients with differing dental scenarios, and different malocclusions.

[0032] In some examples, the transverse pivot has an upper surface and a lower surface, and wherein the interior shape of the receptacle may be such that the transverse pivot can be rotated about the second axis and over an angle between 1° and 30°, specifically between 5° and 15°, and wherein the rotation about the second axis is limited by the upper and / or lower surface touching against an inside of the distal cap, and / or against the distal base. In these examples, moments and forces provoked by torsional forces along the arm of the orthodontic device may be well absorbed by the receptacle.

[0033] In some examples, a centre plane is defined by the first axis and the second axis (at the height of the arm of the mesial element), and wherein the transverse pivot is symmetrical with respect to the centre plane. In some examples, a centre plane is defined by the first axis and the second axis, and the receptacle may be asymmetrical with respect to the centre plane. Asymmetries may be introduced in the device to allow for more rotation in one direction than another. Asymmetries may be present in the transverse pivot and / or in the inside of the distal cap.

[0034] In some examples, a third axis is arranged perpendicular to the first and to the second axis, and an angle between the third axis and the longitudinal axis of the transverse pivot may be between 0° and 15°.

[0035] In a further aspect, a kit comprising an orthodontic device according to any of the herein disclosed examples and one or more rubber bands is provided. The rubber bands are an example of a traction device. Alternative traction devices involving pistons, pins, or other elements may be used as long as a distal force can be provided to the distalization device. Optionally, the kit may further comprise a distal anchor for coupling with the rubber band. Insome examples, the anchor may be a bracket. In other examples, TAD’s (Temporary Anchorage Devices) may be used.

[0036] Additional objects, advantages and features of embodiments of the invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention. In a first aspect of the present disclosure, a grinding device for grinding a root portion of a wind turbine blade is provided. The grinding device comprises a base for attaching the grinding device to the wind turbine blade, a hub attached to the base and an arm rotatably mounted with respect to the hub. The grinding device further comprises a grinding wheel mounted on the arm and an electrical power supply for powering operation of the grinding device configured to move with the base.BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Particular embodiments of the present invention will be described in the following by way of non-limiting examples, with reference to the appended drawings, in which:Figures 1A - 1 B illustrates some of the terminology used herein;Figures 2A - 2E illustrate an example of a mesial and distal element of an orthodontic device according to an implementation; andFigures 3A - 3C show a side view and a cross-sectional top views of a mesial element and a transverse pivot arranged between a distal base and a distal cap according to further examples.DETAILED DESCRIPTION OF EXAMPLES

[0038] Reference now will be made in detail to examples of the present disclosure, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation only, not as a limitation. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure. For instance, features illustrated or described as part of one example can be used with another example to yield a still further example. Thus, it is intended that the present disclosure covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0039] Figure 1A schematically illustrates the arrangement of teeth in the lower jaw (mandible). A front portion of the mouth 110 may be referred to as a mesial region. A rear portion of the mouth 120 may be referred to as a distal region. An inner portion of the mouthbehind the teeth 130 may be referred to as a lingual region. An outer portion of the mouth 140 may be referred to as a labial region. A mesial-distal direction 115 with respect to a specific tooth (first molar) has been schematically indicated in figure 1A. Also indicated in figure 1A is a lingual-labial direction 135 with respect to the same tooth. This terminology will be adhered to in the present disclosure.

[0040] Figure 1 B schematically illustrates a molar. A mesial side of the molar is indicated by reference sign 110, whereas a distal side of the molar is indicated with reference sign 120. Reference signs 130 and 140 respectively indicate the lingual and labial sides of the molar.

[0041] In the present disclosure, a first axis is defined as an axis substantially perpendicular to a base surface of a distal element attached to a lingual surface of the molar. In figure 1 B, the first axis is indicated with reference sign 1 . A second axis may be defined as extending along the mesial-distal direction substantially parallel to the base surface of the distal element. The second axis 2 is perpendicular to the first axis 1.

[0042] Figures 2A - 2E schematically illustrate an implementation of an orthodontic device used for segmental distalization. An orthodontic device comprises a mesial element 10 and a distal element. The mesial element 10 has a base 11 which may be configured to be attached to a canine. The distal element may be configured to be attached to a molar.

[0043] In an example, the mesial element may be attached to a maxillary canine and the distal element may be attached to a maxillary molar or premolar. An anchor for attachment of a traction device such as e.g., a rubber band may then be attached in the mandible.

[0044] In another example, the mesial element may be attached to a canine 51 in the mandible, and the distal element may be attached to a molar 53 in the mandible. In this scenario, an anchor 30 may be attached in the maxilla (see figure 2E).

[0045] In either case, the anchor 30 may be a TAD, a bracket, or molar tube, or any other device which can retain the traction element. In the case of an elastic band 40, the elastic band may be retained on a hook 32 of the anchor 30.

[0046] The mesial element 10 comprises an arm 13 which extends generally in a mesial- distal direction, ending in a transverse pivot 14. The transverse pivot in this example may be substantially condyle shaped. In other examples, other shapes may be chosen.

[0047] As schematically illustrated in figures 2A and 2B, the transverse pivot 14 may be arranged (“sandwiched”) between the distal base 18 and a distal cap 16. The distal cap 16 has an opening at the mesial side through which the arm 13 extends.

[0048] The distal base has a substantially flat upper surface in this example. The bottom surface of the distal cap may also be substantially flat for ease of placement of the distal cap over the distal base. In other examples, the upper surface of the distal base may be inclined or otherwise shaped, and the bottom surface of the distal cap may have a complementary shape.

[0049] The distal base 18 in this example has three holes 20. The function of these holes is to receive three pins 24 arranged at a bottom of the distal cap 16. The holes and pins 24 thus form a male-female coupling to securely attach the distal cap 16 to the distal base 18. At the same time, in this example, the holes and pins function as alignment features allowing correct positioning / alignment of the distal cap with respect to the distal base. With such an arrangement, the correct positioning of the distal cap 16 with respect to the distal base 18 can be ensured.

[0050] In other examples, alignment features may be separate from the male-female connectors for coupling the two elements together. In yet further examples, alignment features may be provided whereas there are no male-female connectors.

[0051] The distal base 18 may further comprise a positioning feature 19 which facilitates the correct positioning of the transverse pivot prior to assembly of the distal cap 16 to the distal base 18. The positioning feature may be e.g., a marking on the distal base. The positioning feature may also be a protrusion or protruding plane on the distal cap. In yet further examples, the positioning feature may be a recess, in which the pivot may be placed. The recess may have a shape that is complementary to a convex bottom surface of the pivot. In yet a further example, the pivot may include a protruding portion (e.g. a dovetail or hook) which can mate with a recess in the distal base. In examples, the mating may comprise snap-fitting.

[0052] In other examples, other numbers of pins and holes may be used. And in further examples, other male-female coupling elements or connectors may be used. For example, the male connector may be a dovetail, and the female connector may be a suitable dovetail slot. Also, the arrangement of the male and female coupling members may be exchanged e.g., pins may be provided on the distal base, and these may be received in openings on the distal cap.

[0053] In examples, after positioning the distal cap over the transverse pivot and onto the distal base 18, the pins may be welded to the holes, optionally ultrasonic welding may be used. In other examples, adhesives may be used to join the pins to the holes. In yet further examples, the pins may be riveted or otherwise mechanically deformed using e.g. coining or stamping. These joining methods may also be combined. The same applies for alternative male-female connectors such as e.g., a dovetail and dovetail slot.

[0054] In addition to, or instead of the male-female coupling described hereinbefore, the distal cap and distal base may be joined to each other in other manners as well. In some examples, the distal cap may comprise a flange configured to be fit around the distal base, and joining the distal cap to the distal base comprises swaging the flange over the distal base.

[0055] In some examples, the distal cap and distal base may be snap-fit together, and optionally wherein the male and female connectors snap-fit together.

[0056] In some examples, the distal cap and distal base may be attached to each other using e.g. a plurality of screws.

[0057] A mesial element 10 comprises a projection 15 around which a rubber band may be arranged. The rubber band 40 may also be arranged around a projection or hook 32 on an anchor 30, thereby exerting force on the projection 15 and thus the mesial element. The anchor 30 may be mounted e.g. to a maxillary molar. In some examples, the anchor could be a bracket or molar tube.

[0058] This way, a force pulling the canine in the mandible backwards (i.e., in the distal direction) is provided. If the patient is wearing e.g., a splint (or another fixation device) that acts as a solid anchor and fixes the teeth of the maxilla in position, it may be ensured that the teeth in the maxilla do not move forwards, and that the canine in the mandible is pulled backwards. As noted before, rather than applying a distalization force on a segment of teeth in the mandible, the distalization force may be applied to a segment of teeth in the maxilla.

[0059] Due to the connection between the mesial element 10 and the distal element of the orthodontic device, the molar 53 may thus also be pushed backwards. At the same time, due to the shape of the arm in between the canine and the molar and due to the position of the distal element on the molar, a rotational force is also exerted upon the molar 53. This rotational force may result in a pivot about the palatal root of the maxillary molar. Also, a rotation in the distal direction of the molar (“uprighting”) may result. Thus a backwards force and a rotational force may be exerted upon the molar at the same time.

[0060] In alternative configurations, a traction element other than a rubber band might be used. Pistons, springs and nitinol wires (e.g. shaped into one or more loops) may be used as alternative traction elements.

[0061] In alternative configurations, a different anchor may be used, e.g. a TAD positioned in the palate. In some examples, an anchor may include a threaded hole, and the traction element may be a pin with a mating thread. By threading the pin in the threaded hole, traction can be applied.

[0062] In this example, the projection or hook 15 is provided at a most mesial end of the device. In other examples, the projection of hook may be provided elsewhere, e.g. along the arm 13.

[0063] Figures 2C and 2D illustrate further details of the example of the orthodontic device. The mesial element has a mesial base 11 having a mesial base surface 12 which is configured for being attached to a canine or premolar. The mesial base surface 12 may include a number of protrusions for attachment to a canine. This base surface may be slightly concave to adapt to the specific tooth it needs to be attached to.

[0064] Before attachment, the surface of the tooth may be cleaned, possibly etched and subsequently dried. Then, an adhesive may be applied to the surface of the tooth. It is known to use an adhesive which may be activated using light. The orthodontic appliance, possibly also comprising an adhesive on its base surface may then be attached to the surface of the tooth. The adhesive may spread in the channels formed between the protrusions on the mesial base surface.

[0065] After activation of the adhesive using e.g. light, the orthodontic appliance may be firmly fixed to the tooth. Different types of adhesives may be used, such as e.g. composite resins or glass ionomer cement. This process is also referred to as “bonding”, or, depending on the adhesive used “cement bonding”. Due to the channels that widen towards the edges, improved mechanical retention can be achieved.

[0066] Figures 2C and 2D also illustrate a distal element having a distal base surface 22 adapted to be fixed to a molar surface. Also the distal base surface 22 may comprise a certain roughness or protrusions that aide in bonding to the molar. In the illustrated example, the protrusions may be smaller than on the mesial base surface. The spaces between the protrusions can be occupied by adhesives in order to mechanically retain the distal base surface on the molar.

[0067] In the example of figure 2, the mesial element further comprises a hole 29 for receiving an auxiliary arm. Hole 29 may be a through-hole or a blind hole. Insertion of the auxiliary arm may be carried out by an orthodontist prior or after mounting the orthodontic device in a mouth of the patient.

[0068] The auxiliary arm may be a (threaded) pin for example. The auxiliary arm might also be a resin. The auxiliary arm may be used for introducing a further force on the orthodontic device (in addition to the distalization forces which may result from the rubber bands for example).

[0069] In the illustrated example, the hole 29 may be arranged adjacent to the hook 15 and adjacent to the mesial base surface. In other examples, hole 29 for introduction of the auxiliary arm may be position more distally. In yet further examples, more than one such holes 29 may be provided.

[0070] Figure 3A shows a cross-sectional top view of a transverse pivot arranged between a distal base and a distal cap to an example. A longitudinal axis of the transverse pivot is indicated with reference sign 4. The third axis indicated with reference sign 3 may be defined as perpendicular to the first axis and to the second axis defined in figure 1 B. First axis 1 as defined in figure 1 B is also schematically indicated.

[0071] In this example, axes 3 and 4 coincide before rotation. An angle between the longitudinal axis 4 of the transverse pivot 14 and the third axis 3 may be between 0° and 20°. The angle may vary during a treatment, as a molar rotates as it is pushed backwards by arm 13. The rotation of the molar results in a rotation around the first axis, perpendicular to the second axis and third axis 3.

[0072] The limitation of the rotation around the first axis is limited by a mesial surface 14b touching against a mesial inner wall 25 of an inside of the distal cap. The limitation of the rotation around the first axis may also be limited by a distal surface 14a touching against a distal inner wall 26 of the distal cap.

[0073] A second orientation of the same mesial element including arm 13 and transverse pivot 14 is shown in an interrupted line.

[0074] Figure 3B schematically illustrates the mesial element 10 of this example, including transverse pivot at its most distal end.

[0075] Figure 3C shows a cross-sectional top view of a transverse pivot in a receptacle of the distal element according to a further example. In the example illustrated in figure 3C, the transverse pivot has a varying cross-section along the longitudinal axis. From a central point where a transverse pivot 14 is connected to arm, the cross-sectional dimension decrease in both directions to ends 14c and 14d.

[0076] The effect if this decrease is that the increase in contact between pin and receptacle (and thus resistance to further rotation) is more gradual.

[0077] The different components of the orthodontic device may be manufactured in a variety of ways, including moulding, additive manufacturing like 3D printing, machining or other. The different components may be made of a variety of suitable materials, including metals (e.g.stainless steel or titanium), ceramics, plastics (e.g. PEEK, polysulfones and others), or composites (e.g. fibre reinforced polymers).

[0078] In a specific example, placing the distal cap over the pivot may comprise 3D printing the distal cap over the distal base, when the pivot has already been positioned on the distal cap.

[0079] Although in the present disclosure and in the figures, a distalizer with a substantially condyle-shaped pivot has been shown, it should be clear that the illustrated and described methods for assembly are generally applicable with other pivots as well. In particular, the pivot elements such as described in EP 1 433 435, EP 1 649 824 and in WO 2018 / 219858. In particular, the pivot may be substantially ball-shaped, or may be shaped as a ball with diametrically opposed planer surfaces, or may be a substantially elongate pin.

[0080] Although only a number of particular embodiments and examples of the invention have been disclosed herein, it will be understood by those skilled in the art that other alternative embodiments and / or uses of the invention and obvious modifications and equivalents thereof are possible. Furthermore, the present invention covers all possible combinations of the particular embodiments described. Thus, the scope of the present invention should not be limited by particular embodiments, but should be determined only by a fair reading of the claims that follow.

Claims

CLAIMS1 . A method for assembling a distalization device, the method comprising: providing a mesial element having a mesial base surface configured for attachment to a premolar or a canine, a projection for coupling with a traction element, and an arm, wherein the arm comprises a pivot at a distal end of the arm; providing a distal base with a distal base surface configured for attachment to a molar; positioning the pivot on the distal base; placing a distal cap over the pivot so as to enclose the pivot between the distal base and the distal cap; and joining the distal cap to the distal base.

2. The method of claim 1 , wherein the distal cap and / or the distal base comprises alignment features for aligning the distal cap with the distal base when placing the distal cap over the pivot.

3. The method of claim 1 or 2, wherein the distal cap is joined to the distal base with one or male-female couplings.

4. The method of any of claims 1 - 3 wherein the distal cap comprises one or more male connectors, optionally pins, and wherein the distal base comprises one or more female connectors, optionally holes for receiving the pins.

5. The method of claim 4, wherein joining the distal cap to the distal base further comprises welding the male connectors of the distal cap in the female connectors of the distal base, and optionally wherein the welding is ultrasonic welding.

6. The method of claim 4, wherein joining the distal cap to the distal base further comprises mechanically deforming the male connectors after introduction into the female connectors, and wherein mechanically deforming optionally comprises riveting.

7. The method of any of claims 1 - 6, wherein the distal cap comprises a flange configured to be fit around the distal base, and wherein joining comprises swaging the flange.

8. The method of any of claims 1 - 7, wherein the distal cap and distal base are snap-fit together, and optionally wherein the male and female connectors snap-fit together.

9. The method of any of claims 1 - 8, wherein the distal base comprises a positioning feature for facilitating the positioning of the pivot on the distal base.

10. The method of any of claims 1 - 9, wherein the pivot is substantially condyle-shaped, or ball-shaped, or wherein the pivot is ball-shaped with diametrically opposed planar surfaces11. An orthodontic device for segmental distalization of a posterior jawbone area comprising: a mesial element having a mesial base surface configured for attachment to a premolar or a canine, a projection for coupling with a traction element and an arm, wherein the arm comprises a transverse pivot at a distal end of the arm, a distal element having a distal base configured for attachment to a molar, and a distal cap, wherein the transverse pivot is arranged between the distal base and the distal cap.

12. The orthodontic device of claim 11 , wherein the distal base comprises a distal base surface for attachment to a surface of the molar and wherein a first axis is defined as being substantially perpendicular to the distal base surface, and a second axis is defined as a mesial- distal direction substantially parallel to the distal base surface and substantially perpendicular to the first axis, and wherein the transverse pivot has a mesial surface and a distal surface, wherein an interior shape of the distal cap is such that the transverse pivot can be rotated about the first axis over an angle between 1° and 45°, and wherein the rotation about the first axis is limited by the mesial and / or distal surface touching against an inside of the distal cap.

13. The orthodontic device according to claim 12, wherein the transverse pivot can berotated about the first axis between 5° and 20°, optionally between 8° and 15°.

14. The orthodontic device according to claim 12 or 13, wherein the transverse pivot has an upper surface and a lower surface, and wherein the interior shape of the distal cap is such that the transverse pivot can be rotated about the second axis and over an angle between 1° and 30°, specifically between 5° and 15° and wherein the rotation about the second axis is limited by the upper surface touching against an inside of the distal cap and the lower surface touching against the distal base.

15. The orthodontic device according to any of claims 11 - 14, wherein the transverse pivot is substantially condyle-shaped.

16. The orthodontic device according to any of claims 11 - 15, wherein the transverse pivot has two rounded ends.

17. The orthodontic device according to any of claims 11 - 16, wherein the distal cap has an opening at a mesial side, and optionally wherein an edge of the opening of the mesial side limits the rotation of the transverse pivot about a longitudinal axis of the transverse pivot.

18. The orthodontic device according to any of claims 11 - 17, further comprising a hole for introduction of an auxiliary arm.

19. The orthodontic device according to any of claims 11 - 18, wherein the transverse pivot has a longitudinal axis and a receptacle formed between distal cap and distal base is such that the transverse pivot can be rotated about the longitudinal axis over an angle between 0° and 60°, specifically between 15° and 45°.

20. The orthodontic device according to any of claims 11 - 19, wherein the projection of the mesial element is a hook.

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