An intra oral appliance

Abstract

An internal frame for an intra oral appliance comprises a web having an anterior portion and left and right arm portions on each side of the anterior portion. The web may comprise three flex formations spaced from each other on the anterior portion of the web that permit the web to flex for enabling the web to be deformed to accommodate different users. Each flex formation may comprise a recess extending from a lingual edge of the web in a direction inward towards the buccal edge of the web. The internal frame may further comprise a buccal wall extending substantially orthogonally away from the web. An intra oral appliance including the internal frame which is encased within a surround member is also disclosed.

Description

[0001] AN INTRA ORAL APPLIANCE

[0002] FIELD

[0003] This invention relates to an internal frame for an intra oral appliance. This invention extends to an intra oral appliance including the internal frame.

[0004] This invention relates particularly, but not exclusively to an internal frame for an intra oral orthodontic appliance. It extends to an intra oral orthodontic appliance including the internal frame and a method of treating a user. It will therefore be convenient to hereinafter describe the invention with reference to this example application. However, it is to be clearly understood that the invention is not to be limited to orthodontic appliances. It extends to intra oral appliances used for all other purposes.

[0005] BACKGROUND

[0006] The Applicant is aware of pre-moulded appliances for treating malocclusions. One such pre-moulded appliance is a MYOBRACE® appliance which is worn by a user while sleeping, and optionally at other times as well, for treating a class 2 malocclusion. An example of a MYOBRACE® appliance is disclosed in AU 2005330526 published on 19 October 2006.

[0007] Figures 1 a and 1 b illustrates an example of a prior art MYOBRACE® appliance. The MYOBRACE® appliance comprises an internal frame providing some skeletal strength and rigidity. It also comprises a cushioning surround member encasing the internal frame that bears against the intra oral structures of the user. The cushioning of the surround member can be soft which makes the appliance more comfortable for a user to wear. The internal frame, and also the appliance generally, has a web lying in the occlusal plane and a prominent buccal wall extending transverse to the occlusal plane along the buccal edge of the web. As shown in the drawings, an anterior portion of the web of the internal frame is intentionally designed with considerable rigidity. It comprises two broadly parallel rail sections extending along buccal and lingual edges of the web respectively and several transverse sections extending between the buccal and lingual rail sections. A central transverse section of the anterior portion is particularly wide and sturdy, as shown in the Figure 1 b drawing. The transverse sections extending between the two rail sections further stiffen the anterior portion of the web. This arrangement confers substantial rigidity on the web and resists deformation of an anterior portion of the internal frame and appliance in the occlusal plane.

[0008] This design feature confers a high spring strength on the anterior portion of the web of the internal frame. Consequently, when the appliance is fitted to a user and the anterior portion of the internal frame is deformed to fit the appliance onto the arch forms of the user, the anterior portion of the web of the frame applies a return spring force onto the arch form of the user. When the appliance is fitted to a user having a class 2 malocclusion with an underdeveloped and narrow arch form, the spring force of the deformed frame encourages expansion of the narrow arch form. The MYOBRACE® appliance has been useful for treating class 2 malocclusions on users in the mixed dentition stage in which the maxillary and mandibular bones of the user are still developing.

[0009] The reference to prior art in the background above is not and should not be taken as an acknowledgment or any form of suggestion that the referenced prior art forms part of the common general knowledge in Australia or in any other country.

[0010] SUMMARY OF DISCLOSURE

[0011] Applicant recognises that the rigidity of an anterior region of the internal frame of the MYOBRACE® appliance (which promotes arch expansion) limits the range of different arch forms to which the appliance can be fitted. For example, if a user’s arch form is significantly different to the arch form defined by the appliance in its resting configuration, the appliance cannot be fitted to them. The anterior region of the internal frame simply does not have a sufficient degree of flexibility to enable the appliance to fit overthe significantly different arch form. This has limited the range of different people that can be treated with a MYOBRACE® appliance.

[0012] Applicant recognises that it would be beneficial if a new appliance could be developed that could be used to treat patients or users having a wider range of arch forms and arch configurations. Applicant recognises it would be further advantageous if an intra oral appliance could be devised that conferred new and additional treatment options for expanding an arch form of a user. Additionally, Applicant believes it would also be beneficial if a new appliance could be devised that can help to align a user’s dentition, e.g. aligning and straightening teeth, irrespective of their stage of development. According to one aspect of the invention there is provided an internal frame for an intra oral appliance comprising: a web comprising an anterior portion and left and right arm portions on each side of the anterior portion, the web extending in a plane and having a buccal edge and an opposed lingual edge, the web comprising at least one flex formation that permits the web to flex in the plane of the web for enabling the internal frame to accommodate users having different arch forms; and a buccal wall extending substantially orthogonally away from the web along the buccal edge thereof.

[0013] The at least one flex formation may be positioned on the anterior portion of the web.

[0014] The at least one flex formation may comprise a first flex formation positioned on a midline of the web of the internal frame.

[0015] The at least one flex formation may further comprise second and third flex formations on either side of the first flex formation.

[0016] Each of the second and third flex formations may be broadly aligned with the canine teeth of a user. For example, the second flex formation may be broadly aligned with the user’s canine teeth on the left side, and the third flex formation may be broadly aligned with the user’s canine teeth on the right side.

[0017] Each flex formation may comprise a recess formed in the lingual edge of the web that extends in a direction towards the buccal edge.

[0018] Each recess may comprise two spaced sides (or side edges) extending in from the lingual edge of the web and a rounded inner end (or inner edge) remote from the lingual edge.

[0019] Each recess may extend a length of at least 80% of the distance or length from the lingual edge of the web to the buccal edge thereof, (e.g. in a direction orthogonal to the lingual edge).

[0020] The recess forming the second flex formation and the recess forming the third flex formation may have the same size and configuration. Further, the recess forming the first flex formation may have a different size and configuration to the second and third flex formations. Each recess may have a dimension of length and width, and the length can be selected to engineer the bendability of the flex formation.

[0021] The internal frame may be formed of a polyamide material having some rigidity, and the internal frame may be integrally formed as a homogeneous unitary article by injection moulding of the polyamide material.

[0022] The web may further comprise a plurality of apertures on each of the left and right arm portions.

[0023] The plurality of apertures on each of the left and right arm portions may comprise a pair of apertures closely spaced from each other, and each pair of closely spaced apertures may be positioned adjacent to the anterior portion.

[0024] The buccal wall may comprise an anterior portion extending across at least the incisors of a user.

[0025] The buccal wall may further comprise left and right arm portions extending along the left and right arm portions respectively of the web for extending across the molars of the user in use.

[0026] The left and right arm portions of the buccal wall may be separate from the anterior portion and define or form a gap in the buccal wall between the anterior portion and each of the left and right arm portions. Each gap may be posterior to the canine teeth of a user, e.g., between the canine teeth and the premolars.

[0027] The anterior portion of the buccal wall may comprise an upper section extending above the web for extending across the buccal surface of the incisors on the upper arch, and a lower section extending below the web for extending across the buccal surface of the incisors on the lower arch.

[0028] Further, each of the left and right arm portions may comprise an upper arm section above the web, and a lower arm section below the web.

[0029] The upper arm section of each of the left and right arm portions may comprise two wall formations arranged in series along the length of the arm portion, and each arm formation may define an internal window or aperture. The internal frame may include any one or more of the features, or combination of features, of the internal frame defined or described in any other aspect of the invention.

[0030] According to another aspect of the invention there is provided an internal frame for an intra oral appliance comprising: a web comprising an anterior portion and left and right arm portions on each side of the anterior portion, the web extending in a plane and having a buccal edge and an opposed lingual edge, the web comprising three flex formations spaced from each other, wherein each flex formation permits the web to flex in the plane of the web for enabling the internal frame to accommodate users having different arch forms; and a buccal wall extending substantially orthogonally away from the web along the buccal edge thereof.

[0031] The three flex formations may be positioned on the anterior portion of the web and permit the web to flex about an axis extending substantially perpendicular to the plane of the web.

[0032] The three flex formations may comprise a first flex formation positioned on a midline of the internal frame, and second and third flex formations on either side of the midline.

[0033] The second and third flex formations may be bilaterally symmetrical about a midline of the internal frame and may be broadly aligned with the canine teeth of a user.

[0034] The three flex formations have flex properties or characteristics that are different from the remainder of the anterior portion of the web. In particular, the web may be more flexible or bendable at the positions of the three flex formations than the remainder of the anterior portion of the web.

[0035] The three flex formations may permit some bending of the web and the internal frame in the plane of the web at the position or point of each flex formation, for enabling the internal frame to be deformed out of its resting configuration and fitted to the arch forms of different users.

[0036] At least one flex formation may comprise a recess formed in the lingual edge of the web that extends in a direction towards the buccal edge. Preferably, each flex formation comprises a recess formed in the lingual edge of the web that extends in a direction towards the buccal edge. Each recess may comprise two spaced sides extending away from the lingual edge of the web, and a rounded inner end of the recess at inner ends of the spaced sides remote from the lingual edge.

[0037] Optionally, the two spaced sides may taper in towards each other in a direction extending from the lingual edge to the rounded inner end.

[0038] At least one recess, e.g. each recess, may a distance of at least 80% from the lingual edge to the buccal edge of the web, e.g. at least 80% of the distance across the width of the web. In some forms, the recess may extend a distance of at least 90% across the width of the web, and in at least one form substantially fully across the width of the web. The width of the web may be a distance from the lingual edge of the web to the buccal edge thereof. Further, the width of the web may be the width at a point on the web at which the recess is located.

[0039] The distance (or length) of the recess across the width of the web may influence the flex properties of the internal frame. A recess having a greater distance or length can make the flex formation more bendable. By contrast, a shorter recess that extends a shorter distance across the width of the web can make the flex formation more stiff and rigid, and less bendable.

[0040] These features enable the flexibility of the appliance to be engineered for different appliances to suit different clinical applications. For example, an appliance having more rigid flex formations can be designed for a user in mixed dentition or a user with a more severe malocclusion. An appliance having more bendable flex formations can be designed for users with adult teeth or a milder malocclusion.

[0041] The internal frame may be formed of a polymeric material having some rigidity and / or stiffness. In one embodiment, the polymeric material from which the internal frame is formed may be a polyamide material, e.g. a linear polyamide material such as NYLON™.

[0042] The internal frame may be integrally formed as a homogeneous unitary article by injection moulding of the polyamide material.

[0043] The buccal edge and the lingual edge may extend along a length of the web.

[0044] The web may further comprise a plurality of web apertures on each of the left and right arm portions that are arranged in a line along the respective arm portion. The plurality of web apertures on each of the left and right arm portions may comprise a pair of closely spaced web apertures of complementary configuration adjacent to the anterior portion.

[0045] The plurality of web apertures on each arm portion may comprise at least two further web apertures more remote from the anterior portion than the pair of closely spaced web apertures, and the at least two further web apertures may be larger than the pair of closely spaced web apertures. The web apertures increase the surface area of the internal frame in contact with a surround member.

[0046] The buccal wall may comprise an anterior portion that extends across at least the incisors of a user.

[0047] Further, the anterior portion of the buccal wall may comprise an upper section extending above the web for extending across the buccal surface of the incisors on the upper arch, and a lower section extending below the web for extending across the buccal surface of the incisors on the lower arch.

[0048] The upper section of the anterior portion of the buccal wall may comprise a tall section extending across a face of the upper central incisors, and a shorter section extending across the upper outer incisors on left and right sides.

[0049] The lower section of the anterior portion ofthe buccal wall may be substantially shorterthan the upper section and extend across the incisors on the lower arch.

[0050] The buccal wall running longitudinally along the buccal edge of the web may assist in aligning the dentition on the upper and lower arch. The upper section of the anterior portion of the buccal wall may assist in aligning the incisor teeth on the upper arch.

[0051] The buccal wall may further comprise left and right arm portions extending along the left and right arm portions of the web respectively, and the left and right arm portions may extend across the buccal surfaces of the molars of a user in use.

[0052] The left and right arm portions of the buccal wall may be separate from, and spaced from, the anterior portion thereof, and form a gap (or interruption) in the buccal wall between the anterior portion and each arm portion. Thus, the left and right arm portions may be separate from the anterior portion and the gap on each side of the anterior portion may be positioned so that it is posterior to the canine teeth of a user, when fitted to the user.

[0053] Each of the left and right arm portions may comprise an upper arm section above the web and a lower arm section below the web.

[0054] The lower section on each of the left and right arm portions may have a shorter length than the upper section of the arm portions, and each lower section may have a shorter height extending in a direction away from the web than the upper sections.

[0055] Each of the left and right arm portions may comprise two wall formations arranged in series along the length of the arm portion, and each arm formation may define an internal window or aperture in the internal frame that is devoid of frame material.

[0056] The internal window or aperture may occupy at least 50% of the surface area of each wall formation, optionally, at least 80% of the surface area, and in some forms at least 90% or 95% of the surface area. In some embodiments most of the wall formation may comprise a void or window.

[0057] The window or aperture in the buccal wall reduces the amount of material that is required to form the internal frame while still extending around the perimeter of the wall and performing its retention function. The apertures also increase the surface area of the internal frame in contact with a surround member moulded over the frame, and thereby bonding of material of the surround member to the internal frame.

[0058] Optionally, the internal frame may further comprise a lingual wall extending substantially orthogonally away from the web along the lingual edge of the web for stiffening an inner or lingual wall of the appliance. The lingual wall may comprise a short flange that projects above the web. Also optionally, the short flange may extend below the web.

[0059] However, some embodiments of the internal frame do not have a lingual wall.

[0060] According to another aspect of the invention there is provided an internal frame for an intra oral appliance comprising: a web comprising an anterior portion and left and right arm portions on each side of the anterior portion, the web having a buccal edge and an opposed lingual edge, the web comprising at least one flex formation that permits the web to flex for enabling the internal frame to accommodate users having different arch forms; and a buccal wall extending away from the web.

[0061] The web may extend in a plane and the at least one flex formation may permit the web to flex in the plane.

[0062] The at least one flex formation may be positioned on the anterior portion of the web.

[0063] Each flex formation may comprise a recess formed in the lingual edge of the web that extends in a direction towards the buccal edge.

[0064] The internal frame may include any one or more of the features, or combination of features, of the internal frame defined or described in any other aspect of the invention.

[0065] According to yet another aspect of the invention there is provided an intra oral appliance comprising: an internal frame as defined in any one of the other aspects of the invention; and a surround member encasing the internal frame for contacting the intra oral structures of a user when fitted to a user, the surround member forming or defining an upper arch channel on one side of the web of the internal frame for receiving an upper arch of a user, and a lower arch channel on an opposite side of the web for receiving a lower upper arch of the user.

[0066] The surround member may be moulded from a cushioning material that conforms to the intra oral structures of a user. The material may be softer and / or more pliable than the internal frame.

[0067] The cushioning material of the surround member may be softer than the intra oral structures of the user against which it bears or abuts in use, e.g. the soft gums, tongue and buccal mucosa of a user. This enables the cushioning material to deform when it contacts the intra oral structures and thereby conform to these structures and enhance user comfort.

[0068] The cushioning material of the surround member may comprise silicone rubber, optionally, a medical grade silicone rubber.

[0069] The internal frame may be formed of a hard material with some stiffness or rigidity that resists deformation but is designed and configured so that it can be deformed or bent when sufficient force is applied to it. The surround member may comprise a surround web extending in the occlusal plane, a surround buccal wall extending transverse to the surround web along a buccal edge of the surround web, and a surround lingual wall extending along a lingual edge of the surround web.

[0070] The surround web, buccal wall, and lingual wall together may define said upper and lower arch channels of the surround member.

[0071] The surround buccal wall may have a longitudinal extent in a direction of length of the wall that extends fully across and covers the buccal wall of the internal frame.

[0072] Further, the surround buccal wall may have a height or vertical extent that depends both above and below the front portion of the buccal wall of the internal frame. Further, the height of the surround buccal wall may taper in a direction from an anterior end of the surround member to a rear end thereof.

[0073] The surround member may further comprise a tongue tag extending in from the lingual wall of the surround member adjacent the upper arch channel.

[0074] The surround member may further comprise a tongue elevator extending in from the lingual wall of the surround member adjacent the lower arch channel. This helps to raise the height of the tongue of a user as a lowered tongue position causes myofunctional problems.

[0075] The intra oral appliance may be a pre-manufactured (pre-moulded) appliance that is made in a plurality of sizes and a size can then be selected to best fit the patient.

[0076] The appliance may further comprise at least one passage passing through an anterior portion of the appliance from a buccal surface of the surround member to a lingual surface of the surround member. Conveniently, the appliance may comprise two said passages.

[0077] Further, the passages may also pass through the anterior portion of the internal frame in addition to the surround member.

[0078] The passages may be suitable for receiving tooling during manufacture for holding the frame in position when the surround member is injection moulded onto the internal frame. Further, the passages may form breathing holes for inhaling air into the mouth of a user.

[0079] The internal frame may include any one or more of the features, or combination of features, of the internal frame defined or described in any other aspect of the invention. The intra oral appliance may be an orthodontic appliance used for encouraging expansion of the upper arch of the user in the mid-facial region and treating a malocclusion. In particular, the appliance may be used for improving or ameliorating a class 2 malocclusion.

[0080] The appliance may also be used for improving alignment of teeth along the upper arch of the user. In particular, the appliance may also be used for aligning teeth along the upper arch in the mid-facial region. Further, the appliance may be used for aligning the molars of the left and right sides of the arch.

[0081] According to another aspect of the invention there is provided a method of treating a user comprising: providing an intra oral appliance as defined in any other aspect of the invention; fitting the intra oral appliance over the upper and lower arches of the user; and causing the user to wear the intra oral appliance fora few hours in a day fora plurality of days.

[0082] The intra oral appliance may be worn on a daily basis when the user is sleeping, e.g. for at least six hours per day.

[0083] Further, the intra oral appliance may be worn for a treatment period of at least two months, and typically it is worn for longer than six months.

[0084] The method may be used for treating a malocclusion.

[0085] The method may also be used for improving the alignment of teeth along the upper arch of the user.

[0086] The method may be particularly suitable for use on adults.

[0087] The intra oral appliance, and the internal frame thereof, may include any one or more of the features, or combination of features, of the oral appliance or internal frame defined or described in any other aspect of the invention.

[0088] BRIEF DESCRIPTION OF DRAWINGS

[0089] An internal frame for an intra oral appliance and an intra oral appliance incorporating the frame in accordance with the invention may be implemented in several different forms. It will be convenient to hereinafter describe in detail several embodiments of the invention with reference to accompanying drawings. The purpose of providing this detailed description is to instruct persons having an interest in the subject matter of the invention how to carry the invention into practical effect. However, it is to be clearly understood that the specific nature of this detailed description does not supersede the generality of the preceding summary section. The detailed description refers to the accompanying drawings, in which:

[0090] Figure 1 a is a part cutaway perspective view of an intra oral appliance known in the prior art;

[0091] Figure 1 b is a plan view of an internal frame for the intra oral appliance in Figure 1 a;

[0092] Figure 2 is a front upper perspective view of an internal frame for an intra oral appliance in accordance with one embodiment of the invention;

[0093] Figure 3 is a rear upper perspective view of the internal frame in Figure 2;

[0094] Figure 4 is a front view of the internal frame in Figure 2;

[0095] Figure 5 is a side view of the internal frame in Figure 2;

[0096] Figure 6 is a top plan view of the internal frame in Figure 2;

[0097] Figure 7 is a partial cutaway top plan view of an intra oral appliance in accordance with one embodiment of the invention encasing the internal frame in Figure 2;

[0098] Figure 8 is a partial cutaway front upper perspective view of the intra oral appliance in Figure 7;

[0099] Figure 9 is a partial cutaway rear upper perspective view of the intra oral appliance in Figure 7;

[0100] Figure 10 is a partial cutaway front view of the intra oral appliance in Figure 7;

[0101] Figure 11 is a partial cutaway side view of the intra oral appliance in Figure 7;

[0102] Figure 12 is a front view showing the external shape and configuration of the intra oral appliance in Figure 7 omitting the internal frame which is encased;

[0103] Figure 13 is a side view showing the external shape and configuration of the intra oral appliance in Figure 7 omitting the internal frame which is encased; Figure 14 is a top plan view showing the external shape and configuration of the intra oral appliance in Figure 7 omitting the internal frame which is encased;

[0104] Figure 15 is an upper perspective view of an intra oral appliance that is a variation on the appliance in Figure 7 with the internal frame visible through a surround member that encases the internal frame;

[0105] Figure 16 is a rear view of the intra oral appliance in Figure 15 with the internal frame visible through the surround member;

[0106] Figure 17 is a top plan view of an internal frame for an intra oral appliance in accordance with another embodiment of the invention;

[0107] Figure 18 is a schematic drawing of two internal frames having different sized recesses forming the flex formations;

[0108] Figures 19 to 22 comprises four schematic drawings showing four different stages of expansion of the intra oral appliance in Figure 7 that can occur during treatment with the appliance;

[0109] Figures 23 to 26 comprises four schematic drawings showing four different stages of expansion of the internal frame encased within the intra oral appliance in Figure 7 that can occur during treatment with the appliance;

[0110] Figures 27 to 30 comprises four schematic drawings showing four different stages of expansion of an upper arch form of a user that can occur during treatment with the intra oral appliance in Figure 7; and

[0111] Figures 31 to 34 comprises four schematic drawings of the appliance of Figure 7 fitted over the upper arch of a user, the drawings showing the expansion of the appliance and the arch form that can occur during treatment with the intra oral appliance.

[0112] DETAILED DESCRIPTION

[0113] Figures 1 a and 1 b illustrate a prior art intra oral appliance for influencing arch development in the mouth of a user. This appliance has already been described in the background section above and does not form part of the invention. Accordingly, it will not be described further in this detailed description.

[0114] Figures 2 to 6 illustrate an internal frame for an intra oral appliance in accordance with one embodiment of the invention. In the drawings, reference numeral 10 refers generally to the internal frame for the appliance.

[0115] The internal frame 10 may comprise a frame body, and the frame 10 or frame body may comprise an anterior portion 12, and left and right arm portions 14 and 16 respectively, extending away from the anterior portion 12 on each side thereof. Further, the frame 10 comprises a web 20 that lies in in the occlusal plane when fitted to a user. The web 20 extends the length of the frame 10 from the anterior portion 12 to rear or posterior ends of the left and right arm portions 14 and 16. The web 20 has a buccal edge or buccal side 22 extending along an outer longitudinal side of the web 20. The web 20 also has a lingual edge or lingual side 24 extending along an inner longitudinal side of the web 20. The frame 10 also comprises a buccal wall 28 extending substantially orthogonally away from the web 20 along the buccal edge 22 thereof.

[0116] In the Figure 2 embodiment, the web 20 has three flex formations 30, 32 and 34 that are spaced from each other across the anterior portion 12 of the internal frame 10. Each flex formation 30, 32, and 34 permits the internal frame 10 to flex, e.g. in the plane of the web 20 about an axis extending perpendicular to the web 20, whereby to enable the frame 10 to be deformed to receive the arch forms of different users. Thus, the three flex formations may permit some flexing of the anterior portion of the web 20, and thereby also the internal frame 10, in the plane of the web 20 for the frame 10 to accommodate different arch forms.

[0117] The three flex formations 30, 32, and 34 comprise a first or central flex formation 30 that is centrally positioned on the midline of the frame 10, a left or second flex formation 32 and a right or third flex formation 34, positioned respectively on either side of the central flex formation 30. The frame 10 is bilaterally symmetrical so that the left and right flex formations 32 and 34 are equidistant from the central flex formation 30 on the anterior portion and have the same shape and configuration. In the illustrated embodiment, the left and right flex formations 32 and 34 extend at an angle of about 30 to 45 degrees from a centre of radius to a midline 38 of the web 20 or the central flex formation 30. As shown in the drawings and especially in Figures 31 to 34, the left and right flex formations 32 and 34 broadly align with the canines on the upper arch of the user when the appliance is fitted. In the illustrated embodiment in Figures 2 to 6, all three flex formations 30, 32, 34 comprise a recess formed in or cut into the lingual edge 24 of the web 20 and extending in a direction towards the buccal edge 22. The central flex formation 30 has a slightly configuration to the flexformation 32, 34 on eitherside thereof. However, otherthan that, the three recesses 30, 32, 34 have a similar size and shape. Each recess comprises two spaced recess sides 40, 42 extending in from the lingual edge 24 of the web 20 and a rounded inner recess end 44 remote from the lingual edge 24. The two spaced recess sides 40 and 42 may optionally taper slightly in towards each other in a direction extending away from the lingual edge 24.

[0118] The buccal wall 28 extends orthogonally away from the web 20 and comprises a discrete anterior portion 50 that extends across the incisors of a user in use and terminates adjacent to the canines. The anterior portion 50 of the buccal wall 28 comprises an upper section 52 above the web 20 for extending across the buccal surface of the incisors on the upper arch. The upper section 52 in turn comprises a central tall portion or section and a shorter section or portion on each side of the central tall section each of which has large openings or apertures therein as shown in the drawings. The anterior portion 50 further comprises a lower section 54 below the web 20 that is shorter than the upper section 52 and extends across the lower incisors of the user.

[0119] The buccal wall 28 further comprises discrete left and right arm portions 56 and 58 extending along the left and right arm portions of the web 20. The left and right arm portions 56 and 58 are distinct and separate from the anterior portion 50. There is a noticeable gap (or interruption or discontinuity) in the buccal wall 28 between the anterior portion 50 and the left and right arm portions 56 and 58. Thus, the left and right arm portions 56 and 58 are separated from the anterior portion 50 by the gap which in each case is posterior to the canine teeth of a user in use.

[0120] Each of the left and right arm portions 56, 58 comprises an upper arm section 59 above the web 20 and a lower arm section 60 below the web 20. The lower section 60 of each arm portion 56, 58 has a shorter length than the upper section 59 along the arm portion. Further, the lower section 60 of each arm portion 56, 58 has a shorter height or vertical extent (in a direction transverse to the length of the arm portion 56, 58), than the upper section 59.

[0121] The upper arm section 59 of each arm portion 56, 58 comprises two wall formations arranged in series along the length of the arm portion 56, 58. The lower section 60 of each arm portion 56, 58 also comprises two further wall formations (configured differently to the formations on the upper section 59) arranged in series along the length of the arm portion 56, 58.

[0122] Each wall formation of the upper arm section 59 on the buccal wall defines an internal window or aperture that is devoid of frame material. The internal window or aperture may occupy 80% to 90% of the surface area of the wall formation. In some embodiments, most of the wall formation comprises a void or window. The window or aperture in the buccal wall reduces the amount of material that is required to form the internal frame while still extending around the perimeter of the wall. The internal apertures also increase the surface area of the internal frame in contact with a surround material moulded over the frame.

[0123] Figure 18 shows two examples of recesses forming flex formations that are different to the recesses in the web of the frame shown in Figure 6.

[0124] During manufacture of the internal frame the size of the recesses 30, 32, and 34 formed in the web 20 can be varied to vary the resilience of the web 20 and ultimately also the frame 10. Conveniently, this can be done by varying the lengthy or depth of the recess 30, 32, 34 in a direction away from the lingual edge 24 towards the buccal edge 22. A shorter recess 30 will confer a stiffer flex formation in the web 20 of the frame 10. By contrast, a longer recess 30 that extends further towards the opposing buccal edge 22 will produce a more flexible web 20. This thereby provides a technique for engineering the flex of the flex formations to provide different flex properties on different appliances. Additionally, the spacing between the two sides 40, 42 of the recess 30 may also be varied and this may potentially also influence the flex in the flex formation.

[0125] The internal frame 10 is manufactured in an integral form by an injection moulding operation. In the illustrated embodiment the frame 10 is manufactured from a polyamide such as NYLON™. The polyamide may be a long chain synthetic polymeric amide having recurring amide groups as a part of the polyamide chain. The polymer may be linear and, as such, be suited to being formed into a filament although it can be sued to form a three-dimensional body as in the current application. A grade of NYLON™ having a tensile strength of 800- 100, a flexural strength of 1000-1500 and a Rockwell hardness of 90-150 has been found to be particularly suitable for this application. This grade is selected for its hardness and stiffness while still being able to be bent or deformed out of its resting configuration. Further, the NYLON™ has some malleability and ductility. Figure 17 shows a top plan view of an internal frame for an intra oral appliance in accordance with a different embodiment of the invention to that shown in Figures 2 to 6.

[0126] The internal frame in Figure 17 has many similarities to the internal frame in the earlier embodiment shown in Figure 6. Accordingly, the following description will focus on the differences between this embodiment and the Figure 2 embodiment. Further, unless otherwise indicated, the same reference numerals will be used to refer to the same components as in the Figure 2 embodiment.

[0127] The internal frame 10 comprises a web 20 lying in the occlusal plane when an appliance 100 is fitted to a user, and a buccal wall 28 extending substantially orthogonally away from the web 20 along its buccal edge 22. However, in this embodiment, the web 20 has a single flex formation 300 formed therein that is centrally positioned on the midline of the internal frame 10. The single flex formation 300 comprises a recess extending in from the lingual edge 24 of the web 20 and permits the internal frame to flex to some extent about an axis extending perpendicularly to the web 20. The ability of the web of the internal frame to flex about its midline provides some ability to fit the appliance to different users with their own individual arch forms. However, this frame 10 has a more limited ability to be fitted to a range of users than the frame shown in Figure 6.

[0128] Figures 7 to 14 illustrate an intra oral appliance in accordance with an embodiment of the invention incorporating the internal frame shown in Figures 2 to 6.

[0129] The appliance is indicated generally by reference numeral 100 and comprises an internal frame 10 as described above with reference to Figures 2 to 6. It also comprises a surround member indicated generally by reference numeral 102 encasing the frame 10. The surround member 102 is formed of a softer and more resilient material for cushioning the surround member 102 when it bears against the intra oral structures of a user in use. In the illustrated embodiment, the surround member 102 is formed from a silicone rubber, e.g. medical grade silicone rubber which provides a soft cushion that deforms and conforms to the intra oral structures in the mouth of the user, and helps to make the appliance 100 reasonably comfortable for a userto wear. This is an advantageous feature of the appliance 100 because user comfort is an important factor that helps with user compliance.

[0130] The surround member 102 comprises a web 104 extending in the occlusal plane having a buccal edge and a lingual edge, and a buccal wall 110 extending transversely away from the buccal edge of the surround web 104. The surround member 102 also comprises a lingual wall 111 extending transversely away from the lingual edge of the web 104. The surround member 102 defines an upper arch channel 112 on one side of the web 104 for receiving an upper arch of a user, and a lower arch channel 114 on an opposite side of the web 104 for receiving a lower arch of the user. The surround member 102, like the internal frame 10, also comprises a front central portion and a left and right arm portion extending rearward ly therefrom.

[0131] Further, the surround member 102 comprises a tongue tag 116 extending in from the lingual wall 111 of the surround member 102 adjacent the upper arch channel 112. The surround member 102 also comprises a tongue elevator 118 extending in from the lingual wall 111 of the surround member 102 adjacent the lower arch channel 114.

[0132] The buccal wall 110 of the surround member 102 has an upper height or vertical extent that extends above the front or anterior portion of the buccal wall 28 of the frame 10. Further, a lower portion of the buccal wall 110 of the surround member 102 depends, or extends, down below the front or anterior portion of the buccal wall 28 of the frame 10. Further, the height of the buccal wall 110 tapers inward or downward in a direction from an anterior end of the surround member 102 to a rear end of the left and right arm portions as shown in the side view of the intra oral appliance such as Figures 10 and 16.

[0133] The surround member 102 is manufactured by moulding the surround member 102 onto the internal frame 10 once it has been injection moulded. Conveniently, the silicone rubber used to form the appliance may have the following example grade and specification:

[0134] • Hardness of 50-58 according to JIS-A

[0135] • Tensile strength of 7.8 to 9.3 MPa according to JIS-6301

[0136] • Elongation at break 55to 350% according to JIS-6301

[0137] • Tear strength of 43.1 to 49 kN / m according to JIS-6301

[0138] Applicant has used a hard grade of silicone rubber such as KE-1950-70 to make the surround member with some success.

[0139] The moulded intra oral appliance 100 has a resting configuration which is configured to represent correct dental occlusion with the upper arch channel positioned slightly forward of, and outward of, the lower arch channel along their length. In particular, the mid-facial region of the upper arch channel is configured to represent a desired arch form. The appliance can be deformed out of this resting configuration when it is fitted to a user and this deformation applies a return force which acts on the arch form of the user. The return force urges the arch form to develop towards the ‘desired’ arch form represented by the resting configuration.

[0140] The appliance, which is pre-moulded, is manufactured in a range of sizes, e.g. two sizes. In use a pre-manufactured or pre-moulded appliance is selected that best fits the mouth and arch form of the user. The appliance is not custom moulded to match a dental impression of the arch forms of the user.

[0141] In use, the pre-moulded intra oral appliance 100 is fitted to a user by being placed in the buccal cavity or mouth of a user with the upper arch of the user received in the upper arch channel 112 and their lower arch received in the lower arch channel 114. The pre-moulded intra oral appliance 100 has a resting or relaxed configuration that is designed to resemble a desired or preferred arch form for correct dental occlusion. When the appliance 100 is fitted, it is deformed out of the resting configuration to fit the arch form and dentition of that particular user (the size and shape being different for different users). This can involve some bending of the internal frame 10 in the plane of the web 20, which is achieved by bending of the recesses forming the three flex formations, 30, 32, and 34. The ability of the recesses 30, 32, and 34 to flex increases the variation in size and configuration of arch forms in the general population to which the appliance can be fitted to. Therefore, this increases the percentage of people that can be treated with the appliance.

[0142] Once fitted to the upper and lower arches of a user, the deformed frame applies a return force to the arches and dentition of the user tending to expand the anterior portion of the arch form. Further, the return force of the frame also applies a force to the dentition through the buccal wall of the frame and surround member and this helps to align the teeth on the arch form. In particular, it helps to align the premolars and molars on each side of the arch form. It also helps to align the incisors and canines along an anterior mid-facial region of the arch.

[0143] In a further embodiment that has not been illustrated separately, an intra oral appliance like that in Figures 7 to 14 encases an internal frame like that in Figure 17.

[0144] In use, the intra oral appliance containing the internal frame in Figure 17 works in similar fashion to an appliance fitted with the internal frame shown in Figures 2 to 6. However, the appliance 100 with frame 10 in Figure 34 has a lesser ability to flex than the Figure 2 embodiment because it has only one flex formation. Further, while it can flex about the midline of the appliance it does not have as much ability to flex, on either side of the mid line in the region of the canine teeth.

[0145] Figures 15 and 16 show an intra oral appliance that is a variation on the appliance in Figure 7 with the internal frame visible through a surround member that encases the internal frame.

[0146] The appliance in these drawings is similar to that described above with reference to Figures 7 to 14. Accordingly, the following description will focus on the difference between this embodiment and the earlier embodiment shown in Figures 7 to 14. Further, the same reference numerals will be used to refer to the same components as in the earlier embodiments unless otherwise indicated.

[0147] The internal frame 10 in the appliance of Figures 15 and 16 has a different arrangement of apertures formed in the web 20. Further, the recesses 30, 32, 34 are configured differently to those in the earlier embodiment. Additionally, the frame 10 of the appliance 100 in Figures 15 and 16 has an internal or lingual wall 150 extending across the lingual edge 24 of the web 20. The lingual wall 150 is a short wall resembling a flange that projects up above the web 20 and down below the web 20 that helps to stiffen the lingual wall 111 of the surround member 102 and thereby the intra oral appliance 10. The wall 150 extends only a few millimetres above and below the web 20 and extends substantially the full length of the lingual edge 24 of the web 20. As shown in the drawings, the lingual wall 111 is interrupted by the three recesses 30, 32, 34 that open out to the lingual edge 24 of the web 20. Thus, there are gaps in the lingual wall 150 corresponding to the three recesses 30, 32, and 34.

[0148] In use, the intra oral appliance in Figures 15 and 16 can be used in the same way as the appliance in Figures 8 to 14. The lingual wall 150 of the frame 10 acts to stiffen the lingual wall 111 of the appliance 100 when compared with the appliance in Figures 8 to 14. This influences the arch expanding force applied to the arch of the user and it also increases the force aligning the teeth of the user.

[0149] Figures 19 to 22 are schematic plan views of the appliance in Figures 4 to 8 showing differing levels of deformation of the appliance that show how the appliance can expand over time with progression of the treatment. A development of an example arch form through four stages of treatment is shown in Figures 27 to 30.

[0150] Figure 19 shows the appliance in a first configuration. Figure 20 shows an initial expansion of the appliance out of its resting configuration and Figures 21 and 22 show progressively further stages of expansion. Figure 22 indicates a maximum expansion of the appliance 10 at or approaching the resting configuration at the end of a successful treatment. In Figures 21 and 22, and particular in Figure 22, an anterior portion or mid-facial region of the appliance is expanded from that in Figure 19, i.e. it is flatter and wider than that in Figure 19.

[0151] Figures 23 to 26 shows corresponding schematic plan views of the internal frame of the appliance shown in Figures 19 to 22 showing the same four stages of expansion of the frame. The same changes in configuration are observed in these frames over the four figures. The web 20 can expand by deformation of the frame 10 in the plane of the web 20 by being able to bend at each of the recesses forming the flex formations.

[0152] Figures 27 to 30 shows schematic plan views of the upper arch and associated dentition of an example user of the appliance. The upper arch row of teeth comprises two central incisors on each side of the midline in the anterior region of the arch. Outside of that are the two outer incisors, followed by the canines, one on each side of the midline. Thereafter, there is a pre-molar behind each canine and then two molars in line behind each pre-molar.

[0153] This sequence of drawings illustrates a change in the arch form and the teeth that may occur after a treatment program with the appliance in Figures 7 to 14. As shown in the drawings, the arch form has been progressively expanded in the mid-facial region from an initial position in Figure 27 through to stage four shown in Figure 30. Further, Figures 27 to 30 also show an improvement in the alignment of the teeth along the arch form. The alignment of teeth has been improved particularly in the mid facial region comprising the incisor teeth and the canines.

[0154] Figures 31 to 34 show the appliance mounted over the upper arch of the user. This shows how the appliance follows the expansion in the mid-facial region of the arch form of the user over time as the treatment progresses.

[0155] A working advantage of the intra oral orthodontic appliance described above with reference to Figure 7 to 14 is that it can be deformed to enable it to be fitted to users having different arch forms. Further, the internal frame which has a resting configuration and once fitted, it is deformed out of the resting configuration. The deformed frame then applies a return force to the received arches of the user and urging the arch form towards the desired arch form. At least one embodiment of the appliance described above provides new and additional treatment options for expanding an arch form of a user and aligning the dentition on each arch of the user.

[0156] A further working advantage of the appliance described above with reference to Figures 7 to 14 is that the frame of the appliance and thus, the appliance as well, does not apply as strong an arch expanding force in the mid facial region of the arch as the prior art MYOBRACE® appliance described in the background section. This enables the appliance to be fitted to adult users who already have a developed arch form, and the return force applied by the appliance is acceptable and is not too strong for the teeth of the adult. It can therefore be used by adults to improve their arch form and dental occlusion.

[0157] A further working advantage of the appliance described above with reference to Figures 7 to 14 is that it can assist in aligning teeth along the arch form of a user. The left and right arm portions of the appliance can help to align the pre-molars and the molars along left and right sides of the arch. Further, the anterior or front portion can help to align the four incisor teeth along the anterior portion of the appliance.

[0158] There is a gap or discontinuity along the buccal wall of the internal frame between the anterior portion and each of the left and right arm portions thereof. The gap may help to accommodate different canine positions on the arch of the user and additional flexibility when fitting the appliance to the user. The force applied by the appliance then gradually moves the canine teeth towards alignment with their adjacent teeth on the arch form of the user.

[0159] In this specification, the term ‘comprising’ is intended to denote the inclusion of a stated integer or integers, but not necessarily the exclusion of any other integer, depending on the context in which that term is used. This applies also to variants of that term such as ‘comprise’ or ‘comprises’.

[0160] It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. All such modifications and variations thereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad scope and ambit of the invention as is set forth herein. Changes in detail or structure may be made without departing from the basic elements of the invention as defined in the following claims.

Claims

CLAIMS:1 . An internal frame for an intra oral appliance comprising: a web comprising an anterior portion and left and right arm portions on each side of the anterior portion, the web extending in a plane and having a buccal edge and an opposed lingual edge; the web comprising at least one flex formation that permits the web to flex in the plane of the web for enabling the internal frame to accommodate users having different arch forms; and a buccal wall extending substantially orthogonally away from the web along the buccal edge thereof.

2. An internal frame for an intra oral appliance according to claim 1 , wherein the at least one flex formation comprises a first flex formation positioned on a midline of the web of the frame.

3. An internal frame for an intra oral appliance according to claim 2, wherein the at least one flex formation further comprises second and third flex formations on either side of the first flex formation.

4. An internal frame for an intra oral appliance according to claim 3, wherein each of the second and third flex formations is broadly aligned with the canine teeth of a user.

5. An internal frame for an intra oral appliance according to any one of claims 1 to 3, wherein each flex formation comprises a recess formed in the lingual edge of the web that extends in a direction towards the buccal edge.

6. An internal frame for an intra oral appliance according to claim 4, wherein each recess comprises two spaced sides extending in from the lingual edge of the web and a rounded inner end remote from the lingual edge.

7. An internal frame for an intra oral appliance according to claim 5 or claim 6, wherein each recess extends a length of at least 80% of the distance from the lingual edge of the web to the buccal edge thereof at the position of the recess.

8. An internal frame for an intra oral appliance according to any one of claims 5 to 7, wherein the recess forming the second flex formation, and the recess forming the third flex formation have the same size and configuration, and the recess forming the first flexformation has a different size and configuration to the recess forming the second and third flex formations.

9. An internal frame for an intra oral appliance according to any one of claims 5 to 8, wherein each recess has a dimension of length, and the length can be selected to engineer the bendability of the flex formation.

10. An internal frame for an intra oral appliance according to any one of claims 1 to 9, wherein the internal frame is formed of a polyamide material, and the internal frame is integrally formed as a homogeneous unitary article by injection moulding of the polyamide material.

11. An internal frame for an intra oral appliance according to any one of claims 1 to 10, wherein the web further comprises a plurality of apertures on each of the left and right arm portions.

12. An internal frame for an intra oral appliance according to claim 11 , wherein the plurality of apertures on each of the left and right arm portions comprise a pair of apertures closely spaced from each other, and each pair of closely spaced apertures is positioned adjacent to the anterior portion.

13. An internal frame for an intra oral appliance according to any one of claims 1 to 12, wherein the buccal wall comprises an anterior portion extending across at least the incisors of a user.

14. An internal frame for an intra oral appliance according to claim 13, wherein the buccal wall further comprises left and right arm portions extending along the left and right arm portions respectively of the web for extending across the molars of the user in use.

15. An internal frame for an intra oral appliance according to claim 14, wherein the left and right arm portions of the buccal wall are separate from the anterior portion and form a gap in the buccal wall between the anterior portion and each of the left and right arm portions.

16. An internal frame for an intra oral appliance according to claim 14 or claim 15, wherein the anterior portion of the buccal wall comprises an upper section extending above the web for extending across the buccal surface of the incisors on the upper arch, and alower section extending below the web for extending across the buccal surface of the incisors on the lower arch.

17. An internal frame for an intra oral appliance according to claim 16, wherein each of the left and right arm portions comprises an upper arm section above the web, and a lower arm section below the web, and the upper arm section of each of the left and right arm portions comprises two wall formations arranged in series along the length of the arm portion, and each arm formation defines an internal window or aperture.

18. An internal frame for an intra oral appliance comprising: a web comprising an anterior portion and left and right arm portions on each side of the anterior portion, the web extending in a plane and having a buccal edge and an opposed lingual edge, the web comprising three flex formations spaced from each other on the web, wherein each recess formation permits the web to flex in the plane of the web for enabling the web to be deformed to accommodate users having different arch forms; and a buccal wall extending substantially orthogonally away from the web along the buccal edge thereof.

19. An internal frame for an intra oral appliance according to claim 18, wherein the three flex formations comprise a first flex formation positioned on a midline of the internal frame, and second and third flex formations on the anterior portion on either side of the midline.

20. An internal frame for an intra oral appliance according to claim 19, wherein the second and third flex formations are broadly aligned with the canine teeth of a user.

21. An internal frame for an intra oral appliance according to any one of claims 18 to claim 20, wherein each flex formation comprises a recess formed in a lingual edge of the web extending in a direction towards the buccal edge.

22. An intra oral appliance comprising: an internal frame as defined in any one of claims 1 to 21 ; and a surround member encasing the internal frame for contacting the intra oral structures of a user when fitted, the surround member defining an upper arch channel on one side of the web for receiving an upper arch of a user, and a lower arch channel on an opposite side of the web for receiving a lower arch of the user.

23. An intra oral appliance according to claim 22, wherein the surround member is made of a material that is softer than the internal frame and cushions the appliance against the intra oral structures of a user.

24. An intra oral appliance according to claim 22 or claim 23, wherein the surround member comprises a surround web extending in the occlusal plane, a surround buccal wall extending transverse to the surround web along a buccal edge of the surround web, and a surround lingual wall extending along a lingual edge of the surround web, and the surround web, buccal wall and lingual wall together define said upper and lower arch channels.

25. An intra oral appliance according to claim 24, wherein the surround member comprises a tongue tag extending in from the lingual wall of the surround member adjacent to the upper arch channel, and / or the surround member comprises a tongue elevator extending in from the lingual wall of the surround member adjacent to the lower arch channel.

26. A method of treating a user comprising: providing an intra oral appliance as defined in any one of claims 23 to 25; fitting the intra oral appliance over the upper and lower arches of the user; and causing the user to wear the appliance for a few hours each day for a plurality of days.

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