Orthodontic Brackets

Abstract

An orthodontic bracket comprising: a base having a rear surface and a front surface, the rear surface configured to be adhered to a surface of a tooth (outside/labial and/or inside/lingual) in use; and an archwire holder which is rotationally mounted to the front surface of the base, the archwire holder being configured to be rotatable around an axis which is perpendicular to the base to within +/−30°, wherein the archwire holder comprises at least one slot configured to hold an archwire in use, and wherein the archwire holder is rotatable for receiving the archwire and applying a desired amount and/or orientation of tip and/or torque to the tooth in use.

Claims

1. An orthodontic bracket comprising: a base having a rear surface and a front surface, the rear surface configured to be adhered to a surface of a tooth in use; and an archwire holder which is rotationally mounted to the front surface of the base, the archwire holder being configured to be rotatable around an axis which is perpendicular to the base to within +/−30′, wherein the archwire holder comprises at least one slot configured to hold an archwire in use, and wherein the archwire holder is rotatable for receiving the archwire and applying a desired amount and/or orientation of torque to the tooth in use.

2. An orthodontic bracket according to claim 1, wherein the archwire holder is rotatable for receiving the archwire and applying a desired amount and/or orientation of both tip and torque to the tooth in use.

3. An orthodontic bracket according to claim 1, wherein the archwire holder comprises a plurality of slots disposed at different angular orientations, each slot being configured to hold an archwire in use, and wherein the plurality of slots each have a different configuration to apply a different amount and/or orientation of tip and/or torque to the tooth in use, the archwire holder being rotated to select a desired slot for receiving the archwire in order to apply a desired amount and/or orientation of tip and/or torque to the tooth in use.

4. An orthodontic bracket according to claim 1, further comprising a releasable locking mechanism configured to allow the archwire holder to be rotated around the axis of rotation and locked in a plurality of angular orientations, the archwire holder being rotated and locked in place for receiving the archwire in order to apply the desired amount and/or orientation of tip and/or torque to the tooth in use.

5. An orthodontic bracket according to claim 4, further comprising a spring, wherein the locking mechanism comprises the spring, which is resiliently biased against cooperating components on the base and/or the archwire holder to lock the parts in place in use.

6. An orthodontic bracket according to claim 1, wherein the archwire holder comprises a plurality of rotational positions n for selecting the slot.

7. An orthodontic bracket according to claim 6, wherein the archwire holder is further configured to comprise a plurality of rotational sub-positions for each of the rotational positions n for varying an orientation of the selected slot.

8. An orthodontic bracket according to claim 1, wherein the plurality of slots are configured to provide different amounts and/or orientations of torque whereby one or more of the slots is selectable to receive the archwire or other orthodontic brace devices in use via rotation of the archwire holder around said axis, the selected slot being oriented for receiving the archwire to apply the desired amount and/or orientation of torque.

9. An orthodontic bracket according to claim 8, wherein each slot has a different internal shape or orientation to provide different amounts and/or orientations of torque.

10. An orthodontic bracket according to claim 1, wherein for each slot the archwire holder is configured to enable selection of a plurality of angular orientations of the slot when the archwire is disposed in the slot to adjust the amount and/or orientation of tip whereby the archwire holder has a plurality of positions corresponding to selection of a slot and a plurality of positions for the selected slot to adjust the amount and/or orientation of tip.

11. An orthodontic bracket according to claim 1, wherein the archwire holder is configured to be rotatable only around the axis which is perpendicular to the base to within +/−30°.

12. An orthodontic bracket according to claim 1, wherein the slots are oriented in a direction perpendicular to the base to within +/−45° for insertion of the archwire.

13. An orthodontic bracket according to claim 1, wherein the slots are oriented in a plane parallel to the base to within +/−45° for insertion of the archwire.

14. An orthodontic bracket according to claim 1, wherein each slot is formed from two or more sub-slots aligned to receive the archwire.

15. An orthodontic bracket according to claim 1, wherein the archwire holder is configured to be free to rotate, or have its rotary position constrained by the archwire, a flexible mechanism, a positive location mechanism, a weld and/or an adhesive.

16. An orthodontic bracket according to claim 1, further comprising an archwire retainer which is disposed over the archwire holder to retain the archwire in the archwire holder in use.

17. An orthodontic bracket according to claim 16, wherein the archwire retainer is in the form of a sliding or hinged gate, retention band, ring, or snap on cap.

18. An orthodontic bracket comprising: a base having a rear surface and a front surface, the rear surface configured to be adhered to a surface of a tooth in use; and an archwire holder which is rotationally mounted to the front surface of the base, the archwire holder being configured to be rotatable around an axis which is perpendicular to the base to within +/−30°, wherein the archwire holder comprises at least one slot configured to hold an archwire in use, and wherein the archwire holder is rotatable for receiving the archwire and applying a desired amount and/or orientation of tip to the tooth in use.

19. An orthodontic brace kit comprising: a plurality of orthodontic brackets according to claim 1; and one or more archwires having a cross-sectional shape for fitting into the slots of the orthodontic brackets.

20. An orthodontic brace comprising: a plurality of orthodontic brackets according to claim 1; and an archwire disposed in the slots of the orthodontic brackets.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] To assist understanding of the present disclosure and to show how embodiments may be put into effect, reference is made by way of example to the accompanying drawings in which:

[0041] FIG. 1 illustrates a portion of an orthodontic brace including three adjustable brackets mounted to respective teeth with an arch wire located in slots of the adjustable brackets—the figure includes a more detailed view of one of the adjustable brackets;

[0042] FIG. 2 shows three orthogonal views (on directions A, B and C in FIG. 1) of a rotary archwire holder component of an orthodontic bracket with three equally spaced slots, each having a different torque angle due to variations in the orientation of each slot (the archwire and base plate are not shown for clarity);

[0043] FIG. 3 shows a matrix illustrating various combinations of tip and torque that can be applied for the case of three torque values that can be selected by selecting different slots and three tip values provided by three different fine rotation orientations provided for each slot (less or more combinations can be provided by designing in a lower or greater number of tip and torque values according to the number of slots provided and the number of fine rotation positions available for each slot);

[0044] FIG. 4 shows an adjustable orthodontic bracket in more detail comprising three slots each set at different angles for three different torque settings and five fine rotation positions providing five different tip setting for each of the three torque settings; a central spigot forms the rotational axis and retention mechanism between the base and the rotating archwire holder part; in this version protrusions on the base engage with recesses in the rotary component to form clickable locking positions to facilitate the selection of tip and torque settings (an archwire retainer component over the rotary archwire holder is not shown for clarity);

[0045] FIG. 5 shows the orthodontic bracket of FIG. 4 with an archwire retainer in the form of a polymer band to illustrate how ligation of the archwire into the archwire holder can be achieved;

[0046] FIG. 6 shows the orthodontic bracket of FIG. 4 with an archwire retainer in the form of a snap-on cap to achieve an alternative method of ligation of the archwire into the archwire holder;

[0047] FIG. 7 shows a cutaway section of the orthodontic bracket of FIG. 6; the cap may be colourised or patterned to help camouflage or decorate the device;

[0048] FIG. 8 shows an orthodontic bracket configuration including: external rotary constraints and retention as an alternative to a central spigot; a spring clip locking part to maintain the rotary part in the required rotational orientation; and an alternative ligation snap-on ring to retain the archwire in a slot of the rotary archwire holder;

[0049] FIG. 9 shows an orthodontic bracket configuration including slots that engage the archwire in a plane approximately parallel to the base and tooth; the illustrated arrangement provides three slots enabling three variations of torque to be selected, although other variations with less or more slot variations can be envisaged;

[0050] FIG. 10 shows an orthodontic bracket configuration including: two slots for the archwire, in this case at 90 degrees to each other, each slot having different torque angles giving the potential for up to four torque angles that can be selected (the two slots can be oriented in an upwards or downwards direction giving the four torque settings); and a spring clip that is used to positively locate the tip and torque angle selections, the illustration showing three possible tip angles for each torque setting although more or less of either or both could be designed in; and

[0051] FIG. 11 shows an alternative orthodontic bracket of the invention.

[0052] In the figures, like reference numerals have been used for like parts to aid comparison of the different embodiments. It will be understood that the figures illustrate how the concepts described herein can be embodied in practical orthodontic devices. These figures illustrate only some possible configurations and other variations and combinations can be envisaged.

DETAILED DESCRIPTION

[0053] A typical conventional dental brace includes a plurality of orthodontic brackets, each of which are attached to a respective tooth by an adhesive such as bonding cement. Each bracket is configured to provide a substantially horizontally oriented slot (in use when the bracket is mounted to a user's tooth). A wire known as an archwire is inserted into the slot of each orthodontic bracket so as to exert a force on the bracket and thus on the tooth the bracket is attached to, thereby effecting movement of the tooth. A gate or other retention means can be attached to each bracket to retain the archwire in the slot. The components of the orthodontic bracket are typically formed from stainless steel or a ceramic material. The archwire is typically formed from a metal or an alloy such as nickel-titanium or stainless steel. Standard orthodontic brackets are not designed to be adjustable.

[0054] As described in the background section, a typical course of orthodontic treatment may require a number of adjustments to the orthodontic apparatus being used to move the teeth. Since standard orthodontic brackets are not adjustable in use when they are attached to a user's teeth there are two possible ways to adjust an orthodontic brace during treatment: replace one or more of the orthodontic brackets with a bracket having a different pre-configured setting; or bend the archwire to change the forces on particular brackets in the desired manner. Neither of these procedures is ideal in terms of time, difficulty, discomfort, precision, and/or reliability.

[0055] The present specification describes adjustable brackets which can be readily adjusted to reliably adjust the amount and direction of force, and resultant movement of a tooth, in a desired manner during treatment. The arrangements described herein enable a manufacturer, dentist or other to carry out adjustment operations prior to fitting and/or after fitting in a user's mouth. A major advantage is that the forces applied to each tooth can be individually and accurately customised for that tooth rather than the same forces being applied to all teeth.

[0056] FIG. 1 shows a portion of an orthodontic brace 10 including three adjustable orthodontic brackets 12 mounted to respective teeth 14 with an archwire 16 located in slots 18 of the adjustable brackets 12. The figure also shows a more detailed view of one of the adjustable orthodontic brackets 12 with three possible slots (the arrows A, B, C indicate viewing directions referred to in FIG. 2).

[0057] The orthodontic brackets 12 comprise a base 20 having a rear surface 22 and a front surface 24. The rear surface 22 is configured to be adhered to a surface of a tooth 14 in use. An archwire holder 26 is rotationally mounted to the front surface 24 of the base 20. The archwire holder 26 is configured to be rotatable around an axis which is substantially perpendicular to the base 20 (e.g. to within +/−30°, +/−20°, +/−10°, +/−5°, or +/−3°). In use, the archwire holder 26 may be free to rotate or constrained in a plurality of angular orientations (e.g. by a locking mechanism). The archwire holder 26 comprises a plurality of slots 18 disposed at different angular orientations relative to the axis or rotation of the archwire holder 26. Each slot 18 is configured to hold the archwire 16. The plurality of slots 18 each have a different configuration (e.g. different internal shape/orientation/angle) to apply a different amount and/or orientation of tip and/or torque to a tooth in use. The archwire holder 26 is rotated into place (and may be locked in place) to select a desired slot 18 for receiving the archwire 16 in order to apply a desired amount and/or orientation of tip and/or torque to a tooth in use.

[0058] Orthodontic brackets as described herein can be fixed to the outside/labial/buccal surface and/or the inside/lingual/palatal surface.

[0059] FIG. 2 shows three views of the rotary archwire holder 26 (corresponding to arrows A, B and C in FIG. 1). The rotary archwire holder includes three equally spaced slots (in terms of angular orientation), each having a different torque angle due to variations in the angle of each slot (the archwire and base plate are not shown for clarity). The rotary archwire holder 26 is cylindrical in shape and has a central hole to receive a spigot to rotationally mount the component to a base plate. The rear surface of the rotary archwire holder 26 is planar and is located adjacent a front surface of the base plate as shown in FIG. 1. The front surface of the rotary archwire holder 26 has cut-out portions 28 forming projections 30 to define the slots. The illustrated embodiment has six cut-out portions 28 which can be grouped into three pairs of opposing and aligned cut-out portions forming the three angularly oriented slots. As can be seen in View B and C of FIG. 2, the cut-out portions are twisted relative to each other which causes the archwire to twist by a set amount when disposed in one of the slots. This twisting causes a torqueing force to be applied to an associated tooth in use. The illustrated rotary archwire holder 26 can provide five different settings for torque: one of the slots is neutral (zero torque); each of the other two slots have a non-zero torque setting which can be positive or negative according to the 180° orientation of the rotary archwire holder 26. The slot angles to change the torque settings may be at any angle to suit the prescription.

[0060] FIG. 3 shows a matrix illustrating various combinations of tip and torque that can be applied for the case of three torque values that can be selected by selecting different slots and three tip values provided by three different fine rotation orientations provided for each slot. Two further torque settings can be available for this rotary archwire holder design but have not been shown in FIG. 3. Less or more combinations can be provided by designing in a lower or greater number of tip and torque values according to the number of slots provided and the number of fine rotation positions available for each slot.

[0061] FIG. 4 shows an adjustable orthodontic bracket 12 in more detail comprising three slots (18a; 18b; 18c) having different internal shapes for three different torque settings. Five fine rotation positions providing five different tip settings for each of the three torque settings are provided. A central spigot (not visible) forms the rotational axis and retention mechanism between the base 20 and the rotating archwire holder part 26. In this version, protrusions 32 on the base 20 engage with recesses 34 in the rotary component 26 to form clickable locking positions to facilitate the selection of tip and torque settings (an archwire retainer component over the rotary archwire holder is not shown for clarity).

[0062] FIG. 5 shows the orthodontic bracket of FIG. 4 with an archwire retainer 36 in the form of a polymer band to illustrate how ligation of the archwire 16 into the archwire holder 26 can be achieved.

[0063] FIG. 6 shows the orthodontic bracket of FIG. 4 with an archwire retainer 36 in the form of a snap-on cap to achieve an alternative method of ligation of the archwire 16 into the archwire holder 26.

[0064] FIG. 7 shows a cutaway section of the orthodontic bracket of FIG. 6 including a snap-on cap 36 to retain the archwire 16 within the archwire holder 26. The cap 36 includes a peripheral lip 38 which fits over, and couples with, a complimentary lip 40 on the rotary archwire holder 26. The cap 36 may be colourised or patterned to help camouflage or decorate the device. Also visible in the cutaway view of FIG. 7 is the central spigot 42 for rotationally coupling the rotary archwire holder 26 to the base 20.

[0065] FIG. 8 shows an orthodontic bracket configuration including external rotary constraints 44 for rotationally mounting the archwire holder 26 as an alternative to a central spigot. The illustrated configuration also comprises a spring clip locking part 46 to maintain the rotary part 26 in the required rotational orientation. Further still, the illustrated arrangement also has an alternative ligation snap-on ring 48 to retain the archwire 16 in a slot of the rotary archwire holder 26. One or more of these alternative rotational, locking, and archwire retention configurations may be combined with features of the earlier described orthodontic bracket configurations.

[0066] FIG. 9 shows a yet another orthodontic bracket configuration including an archwire holder 26 which has slots 18 that engage the archwire 16 in a plane approximately parallel to the base 20 and associated tooth. The illustrated arrangement provides three slots 18 enabling three variations of torque to be selected, although other variations with less or more slot variations can be envisaged.

[0067] FIG. 10 shows an orthodontic bracket configuration including a rotatable archwire holder 26 including two slots for the archwire 16, in this case at 90 degrees to each other. Each slot is formed of two sub-slots. Each slot has different torque angles giving the potential for up to four torque angles that can be selected (the two slots can be oriented in an upwards or downwards direction giving the four torque settings). A spring clip 50 is provided to positively locate the tip and torque angle selections, the illustration showing three possible tip angles for each torque setting although more or less of either or both could be designed in.

[0068] FIG. 11 shows an orthodontic bracket configuration including a rotatable archwire holder 26 having three slots 18 for the archwire 16. Each slot 18 comprises two sub-slots configured to house the archwire at the same time and having the same slot angle. An archwire 16 is shown in place in a slot consisting of a pair of sub-slots in FIG. 11. Thus, in use, each slot provides a different torque force, which is secured and indexed according to clinical need by locating the tab 61 of spring 60 into cooperating recesses 62 formed in the archwire holder 26. The torque force is translated from the archwire to the tooth by the profiled (in this case rectangular) archwire 16 cooperating with the profile of the slot 18. The level of tip may be adjusted, fixed and indexed by co-locating a protrusion 63 on the base 20 with cooperating profiles 64 on the spring 60. As a variant, the protrusion may be located on the spring 60 with cooperating profiles being located on the base 20. The example shown in FIG. 11 shows three cooperating profiles corresponding to three different tip positions.

[0069] The slot in the embodiments descripted above may instead be formed by a slot that nevertheless performs the same function as the slot formed by two or more sub-slots.

[0070] The examples described herein are to be understood as illustrative examples of embodiments of the invention. Further embodiments and examples are envisaged. Any feature described in relation to any one example or embodiment may be used alone or in combination with other features. In addition, any feature described in relation to any one example or embodiment may also be used in combination with one or more features of any other of the examples or embodiments, or any combination of any other of the examples or embodiments. Furthermore, equivalents and modifications not described herein may also be employed within the scope of the invention, which is defined in the claims.