Orthodontic device for a dental brace

Abstract

An orthodontic device 10 for use in a dental brace for advancing eruption of a tooth, comprises a body 12 including a base 12a, e.g., of mesh, for bonding to the tooth, an arm 14 extending away from t

Description

The present invention relates to an orthodontic device for use in a dental brace for advancing eruption of a tooth, a dental brace including the orthodontic device, a method of fitting the orthodontic device to a tooth, and methods of cosmetic alignment 5 of teeth using the dental brace. BACKGROUND TO THE INVENTION A dental brace is a device used to re-align a person’s teeth for cosmetic or therapeutic reasons. The brace includes a series of brackets (typically stainless steel) bonded to some or all of the upper set or lower set of teeth, and a brace wire (or archwire) is 10 joined to each of the brackets. Brace wire is often made from nitinol and can remember its shape. When deformed, the brace wire inherently straightens itself to reform its original shape. This applies force to move the teeth over a period of time, typically on the order of months. Different teeth erupt from the gum at different rates. Sometimes, a tooth can be 15 impeded from fully erupting from the gum, for example due to crowding by adjacent CO teeth. This is called a partially erupted tooth. A dental brace can sometimes be used to provide a suitably-sized gap for the partially-erupted tooth to fully erupt into. CXI -j— It is sometimes preferable to wait for all teeth to fully erupt before using a dental brace to align the teeth. If it is preferable to fit a dental brace when there is a partially-erupted 20 tooth, then eruption of that tooth may be accelerated using the dental brace. However, as the tooth erupts further and the brace wire straightens, the force encouraging eruption of the tooth tends to decrease and so full eruption of the tooth takes longer than would be ideal, meaning that the brace must be worn for longer. For a partially-erupted tooth, the optimal position to bond a dental bracket in place is a 25 position inset far enough from the end of the tooth such that - once the tooth is fully erupted - the bracket ends up being aligned with the brackets on adjacent fully-erupted teeth. However, a partially-erupted tooth does not usually have enough exposed surface above the gum line available to bond a conventional dental bracket in the optimal position. 30 To overcome this, there are several options an orthodontist may use to accelerate tooth eruption. One option is sequential bracket placement. The bracket is attached to the tooth as high as possible on the already-erupted surface, and the tooth is partially brought down (or up) via the dental brace. The bracket is then removed and bonded again in a new position, as high as possible on the newly-erupted surface. The process is repeated until the bracket can be bonded in the optimal position. In some cases, this process needs to be repeated four or five times, which can be inconvenient, time-5 consuming and expensive. Another option is the use of elastics. In this case, a bracket is placed on the exposed portion of the partially erupted tooth and elastics (fitted to brackets on upper and lower teeth) are used to help cause the tooth to erupt more quickly. However, it can be uncomfortable to wear and more difficult to clean. Elastics also tend to provide 10 relatively little control over tooth movement. Furthermore, there is a loss of elasticity over time, so the patient needs to remember to change the elastics periodically to mitigate this. Patient compliance is a known issue in that respect. A further option is to perform surgery on the gum. A portion of the gum is removed to expose more of the surface of the partially erupted tooth. The bracket may then be 15 attached at, or closer to, the optimal position. Surgery carries the risk of complications and may lead to gum inflammation or infection, and may require special care to be taken post-surgery. It is also generally more invasive, causes discomfort and requires local anaesthetic to be administered. A fourth option is to place bends in the brace wire which may encourage faster eruption 20 of the partially erupted tooth. However, this may have limited impact in reducing overall eruption time and can also make it harder to brush around the brace wire to remove trapped food, for example. It should be noted that this option is comparatively technique-sensitive. It is very hard to put bends in the nitinol wire due to the shape memory of the wire and, although it is somewhat easier to place bends in stainless 25 steel wire, it can be time-consuming process. The amount of wire activation which can be done ata given time is also limited, so multiple trips to the dentist for wire adjustment are still required in order to erupt the tooth more quickly. It is an object of the present invention to reduce or substantially obviate the aforementioned problems. 30 STATEMENT OF INVENTION According to a first aspect of the present disclosure, there is provided an orthodontic device (or orthodontic bracket) for a dental brace, for use in advancing or accelerating eruption of a tooth, as claimed in claim 1. The orthodontic device allows a partially-erupted tooth to be erupted substantially more quickly and conveniently than existing methods, without the need for surgery. The orthodontic device may be considered as an offset bracket or bracket with offset brace wire portion. That is, a bracket where there is an offset between the base that is 5 bonded to the tooth during use and the wire receiving portion that receives the brace wire during use. The wire receiving portion thus does not directly overlie the base. The offset allows part of the wire to be positioned at or closer to the optimal position, without requiring the optimal position of the tooth to be exposed from the gum. That is, the brace wire deviation up / down to the unerupted region of the tooth generates force 10 on that particular tooth to contribute to substantially faster eruption of the tooth, when the orthodontic device is used in a dental brace. The body of the orthodontic device can be bonded to an exposed surface of the partially erupted tooth and the wire receiving portion is positioned offset from the body by the arm. 15 An archwire may be provided in the wire-receiving portion such that, when viewing the tooth surface face-on, the archwire can be seen to extend across the tooth from side to side. The wire can be secured to the orthodontic device, offset to the side of the bonded region rather than being disposed above the bonded region, relative to the tooth surface. 20 The orthodontic tool does not need to be positioned in the optimal position on the tooth, and therefore mitigates the need for surgery to remove a portion of the gum over the tooth. By providing the wire receiving portion at an offset relative to the body, the brace wire may be positioned at the offset position during an initial visit to a dentist or orthodontist. 25 The force applied by the wire may then be used to pull the partially erupted tooth into a corresponding gap in the person’s teeth. The orthodontic device can speed up eruption of the partially erupted tooth from the gum. The orthodontic device may erupt a partially erupted tooth in comparatively fewer visits to the orthodontist than conventional means. For example, the orthodontic device 30 or tool may substantially fully erupt a partially erupted tooth in a single visit, or two or three visits, to a dentist or orthodontist. For a part of a brace wire which is disposed in the wire receiving portion during use, the axis may be substantially parallel to a plane at the base of the device body. That is, a plane which is in use disposed between the base and the surface of the tooth it is bonded to. It will be appreciated that the axis may be slightly off-parallel, e.g. if the 5 wire-receiving portion is adjusted by a dentist, but is not perpendicular to that plane. The wire receiving portion may comprise a first open end and / or a second open end. The or each open end may be disposed on an axis which is substantially parallel to a plane at the base of the body. The wire receiving portion may comprise a bore or through aperture extending along 10 the axis for receiving the brace wire. The bore or through aperture may be open at both ends for allowing the archwire to pass through. The wire receiving portion may include an open-ended slot extending along the axis for receiving the brace wire. The slot may be U-shaped or C-shaped in cross-section, for example. However, it will be appreciated that the particular shape of the slot is not 15 limited to these specific options and may be any suitable shape for receiving and / or retaining part of an archwire. This can allow the wire to be hooked into the slot, e.g. from the front, rear or top. This can be done without needing to thread the wire through a relatively narrow hole on the left or right side. 20 A surface in the slot or bore of the wire-receiving portion may act as a bearing surface for the archwire to act against for encouraging tooth eruption. The wire-receiving portion may be any suitable structure for part of the brace wire to be attached or secured in order to exert a force along the arm to the body for encouraging tooth eruption. For example, there may be a notch or seat on the arm to 25 which the archwire can be attached or secured. That is, the wire-receiving portion may be part of the arm. The arm may have left and right sides for facing towards the left and right sides of the tooth, when bonded to the tooth. The terms left and right are used with respect to an anatomical frame of reference. 30 The wire receiving portion may be arranged on the arm for allowing the wire to extend in a direction from the left (or right) side of the arm to the right (or left) side of the arm. The wire receiving portion may extend in a direction which is substantially 12 03 26 perpendicular to a longitudinal axis of the arm, and also substantially perpendicular to central axis through the base and top of the device body. With this arrangement, the wire may extend directly across the tooth in a direction from the left side of the mouth to the right side of the mouth. 5 The structure of the wire receiving portion may allow the brace wire to be threaded through, hooked, clipped, attached, mounted, bonded or otherwise secured to the wire receiving portion. The arm may extend in a direction substantially parallel to the lateral plane at the base of the body. Any point along the arm may be considered laterally offset from the base 10 of the body. One or both of the arm and the wire-receiving portion may be disposed to a body-side of the plane at the base of the body. The arm extends substantially radially from the body. The arm may then be arranged substantially parallel to the partially-erupted tooth the device will be bonded to during 15 use. The wire receiving portion may be disposed at any position along the arm. The wire receiving portion may be provided at a fixed position on the arm. The wire receiving portion may be considered to be laterally offset from the base of the body. That is, when viewing the device from its top side, the footprint of the wire-20 receiving portion does not overlie the footprint of the base. The wire receiving portion may be disposed at or towards a distal end of the arm. This allows the wire to bear against the wire-receiving portion at a position which is laterally offset from the base of the body by the length of the arm. The arm may be at least 2mm or 3mm in length. The wire receiving portion may be 25 offset from a centre of the body in a direction along the arm by at least 2mm or 3mm. The arm may be at least 4mm or at least 5mm in length. The wire receiving portion may be offset from a centre of the body in a direction along the arm by at least 4mm or 5mm. Preferably the arm is no longer than about 35mm for use in a dental brace for a person. This correspondingly limits the maximum offset of the wire-receiving portion from the base. Three or more wire receiving portions may be provided on the arm. The two or more 5 wire receiving portions may each be laterally offset from the centre of the body by different distances along the arm. Each wire receiving portion may independently include one or more of the features discussed with respect to the first wire receiving portion. 10 Providing additional receiving portions allows the orthodontist to put the brace wire in the most suitable position on the device for the tooth in question, e.g. to customise the amount of force that is applied to the tooth. In some cases, it may be more appropriate to secure the wire in a receiving portion which is relatively closer to the erupted end of the tooth. This reduces the extent to which the brace wire needs to be bent when fitting the wire to the orthodontic device and a neighbouring set of brace brackets. CXI 15 CXI Where additional receiving portions are provided, the wire can be repositioned from the initial receiving portion to a different receiving portion, once the tooth has erupted a bit further. An appropriate force can thus be applied at different stages of the tooth eruption process. The method of adjusting the orthodontic device is discussed in more detail below. 20 The base may comprise a mesh base or mesh pad. During use, the mesh base may be in contact with a surface of the tooth. The mesh base facilitates bonding of the body to the tooth. The arm may be pre-formed in a curved shape. The arm may be shaped to accommodate the shape of the surrounding teeth, gumline and / or mouth. 25 The arm should be resilient enough not to bend under the force of the brace wire. The orthodontic device (or any part thereof, such as the body, arm and / or wirereceiving portion) may be made of any of metal, metal alloy, ceramic, plastic or a composite material. Any suitable combination of any two or more of the metal, metal alloy, ceramic, plastic and composite material may be used. The material(s) used in 30 the device should be bio-compatible or non-toxic. Plastic or ceramic may be preferred because they can be white or off-white in colour, i.e., a similar colour to the tooth the orthodontic device is bonded to. A white or off-white orthodontic device may be camouflaged in this way and therefore be more discreet. 5 The arm may be adjustable. The arm may comprise a malleable material. The arm may be bendable for adjusting the position of the wire receiving portion relative to the body. This may be beneficial, for example, where the wire receiving portion needs to be bent towards or away from the gumline. The arm may be integrally formed with the body. The or each wire receiving portion 10 may be integrally formed with the arm. Providing the arm and body and / or the arm(s) and wire receiving portion as an integrally-formed structure reduces potential weakness in the structure, which may otherwise be present at a joint between the arm and body and / or a joint between the arm and wire receiving portion. According to a second aspect of the disclosure, there is provided a dental brace 15 comprising a plurality of brackets for bonding to teeth, a brace wire (or archwire), and a securing means for securing the brace wire to the plurality of brackets, in which at least one of the brackets is an orthodontic device according to the first aspect of the invention. The advantages are similar to the first aspect of the invention. The orthodontic device 20 can be bonded to a partially-erupted tooth (assuming a suitable minimum exposed surface to bond to) and can be used encourage faster eruption of that tooth in conjunction with the rest of the dental brace. According to an unclaimed third aspect of the disclosure, there is provided a method of bonding the orthodontic device of the first aspect of the invention to a partially 25 erupted tooth, comprising the step of bonding the orthodontic device to an erupted portion of the partially erupted tooth. The method may comprise the step of bending or otherwise shaping the arm, which can be before and / or after the bonding step. The method may include the step of securing a brace wire to the wire-receiving portion 30 of the orthodontic device. According to an unclaimed fourth aspect of the disclosure, there is provided a method of cosmetic alignment of teeth using a dental brace, comprising the steps of: providing a dental brace according to the second aspect of the invention; bonding each of the plurality of brackets to a respective one of the teeth (using 5 a suitable bonding medium), including bonding the orthodontic device of the first aspect to an erupted portion of a partially erupted tooth; fitting the brace wire to each bracket and through the wire receiving portion of the orthodontic device; and securing the brace wire with securing means. 10 This allows a dental brace to be used to re-align teeth for cosmetic reasons without first having to wait for a tooth (or teeth) to fully erupt. It also avoids the need for surgery on the gum, along with the other advantages of the first aspect of the invention. The method can be used to allow braces to be fitted to a set of teeth where there is no particular malfunction or pathological state. The teeth may simply need realignment for 15 cosmetic purposes, and the partially erupted tooth is merely delaying the point at which a conventional dental brace can be fitted without resorting to surgery on the gum or requiring many visits to reposition a bracket on the partially erupted tooth. The present invention can therefore be used to allow the dental brace to be fitted without these inconveniences. CXI 20 When the brace wire (or archwire) is connected to the brace and the orthodontic device, the device can provide a suitable force necessary to encourage the partially erupted tooth into a fully erupted position. The orthodontic device or tool may thereby accelerate eruption of the partially erupted tooth from the gum. According to an unclaimed fifth aspect of the disclosure, there is provided a method of 25 cosmetic alignment of teeth using a dental brace fitted to a set of teeth, including an orthodontic device according to the first aspect of the invention which includes at least two wire receiving portions, the method comprising the steps of: removing a brace wire from a first wire receiving portion of the orthodontic device; and 30 securing the brace wire, or a replacement brace wire, to a second wire receiving portion of the orthodontic device. The wire may therefore be repositioned during a subsequent visit (or visits) to an orthodontist, if the partially-erupted tooth is not erupted in one go by a dental brace which includes the orthodontic device. With a dental brace has been fitted, the (or each) orthodontic device of the first aspect 5 moves with the associated tooth as it erupts from the gum. That is, as the tooth is pulled down (or up) by the force applied by the wire, the position of the wire receiving portion relative to the adjacent brackets will change. The offset of the first wire receiving portion relative to the adjacent brackets thus decreases, and the force applied by the wire on the orthodontic device and associated tooth may decrease. Moving the wire to 10 a second wire receiving portion can be used to re-establish a more optimal force to continue to encourage eruption of the tooth in a shorter timeframe. 15 CXI CXI 20 Whilst the offset of the second wire receiving portion relative to the adjacent brackets may have been too great initially, as the tooth erupts it approaches an offset corresponding to the initial offset of the first wire receiving portion (i.e. the offset when the brace was first fitted). The position of the second wire receiving portion may then be considered to be in an appropriate position for the brace wire to be moved to. By adjusting the orthodontic device in this manner, an orthodontist can easily tailor the amount of force that may be applied to the tooth throughout the eruption process. The orthodontist may tailor the amount of force applied by the orthodontic device without necessarily removing the brace wire or the orthodontic device itself. The second wire receiving portion may be positioned further from the body than the first wire receiving portion. The second wire receiving portion may have a greater offset from the centre of the body than the offset of the first wire receiving portion from the centre of the body. 25 According to an unclaimed sixth aspect of the disclosure, there is provided a method of removing an orthodontic device from a tooth, comprising the step of detaching or de-bonding an orthodontic device of the first aspect of the invention from a tooth (preferably a fully-erupted tooth). Any aspect of the invention may independently include one or more features presented 30 with respect to any other aspect(s) of the invention. BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which: 5 Figure 1 shows a front perspective view of a first embodiment of an orthodontic device according to the present invention; Figure 2 shows a front perspective view of the orthodontic device of Figure 1, where the arm is in a bent or curved state; Figure 3 shows the orthodontic device of Figure 1 as part of a dental brace on a set of 10 teeth; Figure 4 shows a second embodiment of an orthodontic device according to the present invention; Figure 5 shows a third embodiment of an orthodontic device according to the present CXI invention; and CO 15 Figure 6 shows a fourth embodiment of an orthodontic device according to the present invention. CXI 1        DESCRIPTION OF PREFERRED EMBODIMENTS Referring firstly to Figure 1, an unclaimed embodiment of an orthodontic device according to the present invention is indicated generally at 10. The device 10 is shown 20 from the front side, which is the side visible when a person smiles if the device 10 is fitted to a front or visible side of a tooth. The device 10 is suitable for bonding to a tooth in an upper or lower set of teeth. The device 10 may also be referred to as an orthodontic bracket. The device 10 can be made of any suitable material, including but not limited to: metal, alloy, ceramic, plastic or composite material. 25 The orthodontic device has a body 12. An arm 14 extends outwardly from the body 12. A wire receiving portion 16 is provided on the arm 14, for receiving a brace wire (also referred to as archwire). The body, arm and wire receiving portion are all integrally formed in this embodiment. The body 12 includes a base 12a. The base 12a includes a surface suitable for bonding 30 the orthodontic device 10 to an exposed surface of a partially erupted tooth (26, see Figure 3). The body 12 is substantially wider than it is thick, for providing a low profile when bonded to a tooth. In this embodiment, the body 12 and its base 12a are approximately circular in shape, although square, hexagonal or other shapes (including irregular shapes) are 5 contemplated. The base 12 in this embodiment has a diameter of about 3mm to 5mm. It will be appreciated that in other embodiments the size of the body 12 and / or the base 12a may vary as long as they are suitable for bonding to the intended tooth without overlapping or interfering with any neighbouring teeth during use. 10 The base 12a faces towards the tooth when fitted as part of a dental brace. The body 12 has a front face 18. The front face 18 faces away from the tooth during use. The base 12a in this embodiment can be a mesh base. The mesh base improves bonding between the base body 12 and the surface of the partially erupted tooth. Any suitable biocompatible or non-toxic adhesive may be used to bond the body 12 to 15 the surface of the partially erupted tooth. Conventional tooth-bonding adhesive may be CO used. The arm 14 extends outwards from the side or front face 18 of the body 12 in a direction -j— substantially parallel to a plane at the base (ora plane of the base). In this embodiment, the arm 14 is about 4 mm or 5 mm long. In other embodiments, the length of the arm 20 14 may be shorter or longer as required to provide the wire receiving portion at a suitable displacement from the base 12a. In this embodiment, the wire receiving portion 16 is disposed on an end of the arm 14, distal from the body 12. The wire receiving portion 16 is approximately cylindrical. An aperture or bore 20 is provided through the wire receiving portion 16. The aperture 20 25 is sized and shaped to receive a brace wire during use. The aperture 20 has a substantially circular cross section for receiving a wire, which may also have a substantially circular cross section. The aperture 20 is sized to have a diameter greater than that of typical brace wire, although in some embodiments the aperture size may substantially correspond to the wire diameter. 30 In other embodiments, the brace wire may be received by a slot in the wire receiving portion 16 extending through an edge of the cylindrical wire receiving portion 16. The slot may be disposed through an edge or side of the wire receiving portion 16. Referring now to Figure 2, the arm 14 is shown in a bent or curved state. This can achieved by bending the arm 14 of Figure 1 into that shape, when the arm is made of a malleable material. Alternatively, another embodiment of the device 10 may be formed with the arm in a curved state ab initio. 5 The arm 14 being bendable, or otherwise adjustable, allows the wire receiving portion 16 to be repositioned. Bending the arm 14 around the gum, for example, may be beneficial to avoid it catching the inside of a person’s mouth when fitted to a tooth. Providing a malleable arm 14 allows the orthodontist to tailor the shape of the orthodontic tool 10 to the individual’s mouth. In Figure 2, the arm 14 is shown bent in 10 a direction away from the mesh base. It will be appreciated that the arm may be provided with any suitable curvature or shape, whether that is imparted by bending the arm or as a pre-formed shape. Referring now to Figure 3, a dental brace is generally indicated at 100, and is shown fitted to a set of a person’s teeth. The dental brace 100 includes the orthodontic device 15 10 bonded to a partially erupted tooth 26. The partially erupted tooth 26 is partially erupted from a gum 28. The orthodontic device 10 is fitted in place of a conventional bracket, as part of an otherwise conventional dental brace system. The dental brace 100 has a plurality of metal brackets, one of which is indicated at 30. The metal brackets 30 are bonded to a plurality of teeth 32. In this embodiment, the 20 dental brace 100 is bonded to a plurality of teeth 32 in an upper jaw. It will be appreciated that the dental brace 100 could bonded to a plurality of teeth 32 in a lower jaw. In further embodiments, dental braces 100 could be bonded respectively to a plurality of teeth 32 in both the upper and lower jaw, and may each include one or more orthodontic devices. 25 A length of brace wire 34 is secured to each of the brackets 30 along an axis which passes over centres of exposed portions of each fully erupted tooth. The brace wire 34 is also disposed through the aperture 20 in the orthodontic device 10. The brace wire 34 is bent, curved or otherwise deviates up towards the position of the wire receiving portion, and then back down to the neighbouring bracket 30. That part of the 30 brace wire therefore overlies gum over the unerupted portion of the partially-erupted tooth, and does not pass directly over the body 12 or base 12a. Ligatures 35 or other securing means can be provided on each bracket 30 for securing the brace wire 34 to the bracket 30. In this embodiment, the ligatures 35 are elastic ligatures. A ligature 35 is not required on the body 12 of the orthodontic device 10 because the 5 brace wire 34 is not secured to the body 12. The wire can be held securely by passing through the bore 20. In other embodiments, a ligature 35 or securing means may be provided on the wire receiving means 16, e.g. if there is a possibility for the wire to become detached from the wire receiving portion 16. During use, when the brace has been fitted, the brace wire 34 applies a force on the 10 orthodontic device 10 in a direction extending away from the root of the partially erupted tooth 26. In other words, the brace wire 34 provides a force in a direction away from the gum 28 for bringing the tooth into vertical alignment with the adjacent teeth 32. 15 CXI CXI 20 25 30 In the case where a gap is too small for a partially erupted tooth to erupt into, a conventional dental brace may first be used to laterally move the erupted teeth to provide a suitably-sized gap. Once that gap is available, the orthodontic device 10 may be fitted to the partially erupted tooth and joined to the rest of dental brace via the brace wire. Where conventional braces are already fitted to a set of teeth, the orthodontic device 10 can be fitted to the partially erupted tooth 26 to cosmetically align the tooth with the rest of the teeth by: applying a suitable tooth adhesive or cement to the mesh base of the orthodontic device 10; and bonding the orthodontic device 10 to the erupted portion of the partially erupted tooth 26. The position of wire receiving portion 16 can be adjusted by bending or otherwise shaping the arm 14 to introduce a suitable curvature around the gum. The dental brace 100 can be used to cosmetically align the partially erupted tooth 26 with the other neighbouring teeth, assuming a suitable gap is already present. Fitting the dental brace 100 to teeth may be done by first individually bonding each bracket 30 to the various teeth 32, and bonding the orthodontic device 10 to the erupted portion of the partially erupted tooth 26. Then, the brace wire 34 can be fitted (usually sequentially) to each bracket 30 and at a suitable point passed through the aperture 20 in the orthodontic device 10, and secured to the brackets 30 using the ligatures 35. After the partially erupted tooth has been vertically aligned with the rest of the teeth, i.e. fully erupted, the orthodontic device 10 can be removed from the tooth. A conventional bracket may be attached in its place if the dental brace is to be used for further cosmetic alignment of the teeth. 5 Referring now to Figure 4, a second embodiment of the orthodontic device is generally indicated at 10’. Where the features of the orthodontic device 10’ are not described, they may be considered identical or substantially similar to those of the first embodiment above. Like reference numerals are used for like features. In this embodiment, a second wire receiving portion 16’ is provided. The second wire 10 receiving portion 16’ is substantially identical to the first wire receiving portion 16, except for its position on the arm 14. The second wire receiving portion 16’ is disposed on the arm 14. The second wire receiving portion 16’ is disposed between the body 12 and the first wire receiving portion 16. The second wire receiving portion 16’ has a smaller lateral offset from the body 12 than 15 the first wire receiving portion 16. The second wire receiving portion 16’ has an aperture 20’ like that of the first wire receiving portion 16. The aperture 20’ may pass through the arm 14 or to a side of the arm 14. The second receiving portion 16’ allows the brace wire (34, see Figure 3) to be repositioned from the first portion to provide an appropriate force on the tooth 26 throughout the eruption process. 20 With the device 10’ fitted as part of a dental brace, the brace wire (34, Figure 3) may be repositioned by removing the brace wire (34, Figure 3) from one of the wire receiving portions and re-fitting the brace wire (34, Figure 3), or replacement brace wire, to the other of the wire receiving portions. Here, wire would be removed from the second portion 16’ and wire would then be secured to the first portion 16. 25 It will be appreciated that in other embodiments, additional wire receiving portions 16 may be provided to provide additional options for wire positioning. Referring now to Figures 5 and 6, third and fourth embodiments of the orthodontic device are shown generally at 10” and 10’”. Where the features of the orthodontic devices 10”, 10’” are not described, they can be considered identical or similar to those 30 of the first embodiment. Like reference numerals are used for like features. In these embodiments, the wire receiving portions 16”, 16’” each include open-ended slots 36, 36’, respectively. Similar to the through apertures 20, 20’ of the first and 12 03 26 second embodiments, the open-ended slots 36, 36’ are arranged to receive the brace wire (34, Figure 3) during use. It will be appreciated that the slot could instead be provided in the front side of the wire receiving portion in some embodiments. Referring to Figure 5, a third unclaimed embodiment of the orthodontic device 10” is 5 shown. In this embodiment, the slot 36 through the wire receiving portion 16” has a depth that extends in a direction from the base towards the front face 18 of the body 12. In other words, the slot 36 has a depth that extends in a direction perpendicular to the plane of the base. Referring to Figure 6, a fourth unclaimed embodiment of the orthodontic device 10”’ is 10 shown. In this embodiment, the slot 36’ through the wire receiving portion 16’” has a depth that extends in a direction from an end of the wire receiving portion 16’” distal from the body 12 in a direction towards the body 12. In other words, the slot 36’ has a depth that extends in a direction substantially along the arm. The devices of the third and / or fourth embodiments may have any feature or 15 combination of features of the first and second embodiments, e.g. additional wire receiving portions with a slot or bore. The embodiments described above are provided by way of example only, and various changes and modifications will be apparent to persons skilled in the art without departing from the scope of the present invention as defined by the appended claims.

Claims

1. An orthodontic device for use in a dental brace for advancing eruption of a tooth, the device comprising:a body including a base for bonding to the tooth and a top opposing the5 base;a curved arm extending radially away from the body with respect to a central axis passing through the base and the top; anda first wire receiving portion disposed on the arm in a first position offset from the body, and a second wire receiving portion disposed on the arm in a10 second position offset from the body, the second position being a greaterdistance along the arm from a centre of body than the first position, the wire receiving portions being arranged for receiving part of a brace wire along an axis which in use extends substantially across the tooth.

2. An orthodontic device as claimed in claim 1, in which the axis along which the 15 wire receiving portions are arranged is substantially parallel to a lateral planeat the base.

3. An orthodontic device as claimed in claim 1 or 2, in which at least one wire receiving portion includes an open-ended slot for receiving the wire.

4. An orthodontic device as claimed in claim 1 or 2, in which at least one wire 20 receiving portion includes a bore or through aperture for receiving the wire.

5. An orthodontic device as claimed in any preceding claim, in which the arm has left and right sides for facing towards left and right sides of the tooth, and the wire receiving portions are arranged on the arm for receiving the wire in a direction from the left side to the right side of the arm, during use.25 6. An orthodontic device as claimed in any preceding claim, in which the secondwire receiving portion is disposed at or towards a distal end of the arm.

7. An orthodontic device as claimed in any preceding claim, in which at least one of the wire receiving portions is offset from a centre of the body in a direction along the arm by at least 2mm.30 8. An orthodontic device as claimed in any preceding claim, in which at least oneof the wire receiving portions is offset from a centre of the body in a direction along the arm by at least 3mm.12 03 269. An orthodontic device as claimed in any preceding claim, in which at least one of the wire receiving portions is offset from a centre of the body in a direction along the arm by at least 5mm.

10. An orthodontic device as claimed in any preceding claim, in which the base 5 comprises a mesh base or mesh pad.

11. An orthodontic device as claimed in any preceding claim, in which the orthodontic device is formed of one or more of: metal or metal alloy, ceramic, and plastic.

12. An orthodontic device as claimed in any preceding claim, in which the arm is 10 integrally formed with the body.

13. An orthodontic device as claimed in any preceding claim, in which each wire receiving portion is integrally formed with the arm.

14. A dental brace comprising a plurality of brackets for bonding to teeth, a brace wire, and securing means for securing the brace wire to the plurality of brackets, 15 in which at least one of the brackets is an orthodontic device as claimed in anypreceding claim.

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