Self-ligating orthodontic bracket

Abstract

A self-ligating orthodontic bracket having a body member having a front surface defining a reference plane and a rear surface for connection to a tooth directly or via connection to a bonding base adapted for attachment to a tooth. First and second projections extend forwardly from the body member and an archwire slot is defined by opposed archwire slot surfaces on the projections and by a portion of the front surface of the body member. First and second channels are defined in the first and second projections respectively, with a door disposed in the channels and movable between open and closed positions to selectively provide or prevent access to and from the archwire slot. A bore extends through the first projection and a pin is fixed in the bore and extends into the first channel and is received by a retention channel on a lingual side of the door.

Description

PATENTAttorney Docket No. 7815-9028.01TITLE Self-Ligating Orthodontic Bracket Cross-Reference To Related Application

[0001] This application claims priority from U.S. Provisional Patent Application No. 63 / 734,904, filed December 17, 2024, the disclosure of which is hereby incorporated by reference in its entirety.Field of the Disclosure

[0002] The present disclosure is directed generally to an orthodontic appliance for connecting an archwire to a tooth, and more particularly to an orthodontic bracket that has an archwire slot that is open to the front for insertion or removal of an archwire in the bracket. The opening to the archwire slot can be opened and closed by a movable door.Background

[0003] The following definitions of dental directional terms may be used herein to explain the structure of the orthodontic bracket of the present disclosure:

[0004] Mesial - along and toward the front of the dental arch;

[0005] Distal - along and toward the back of the dental arch;

[0006] Buccal / labial - normal to the dental arch and toward the cheek or lip, for simplicity this will also be referred as the front or forward direction;

[0007] Lingual - normal to the dental arch and toward the tongue, for simplicity this will also be referred to as the back or rear direction;

[0008] Tip - inclination of a bracket or tooth in mesial-distal direction;

[0009] Torque - inclination of a bracket or tooth in labial-lingual direction;PATENTAttorney Docket No. 7815-9028.01

[0010] Occlusal / incisal - toward the biting surface of a tooth;

[0011] Gingival - toward the gums; for simplicity the gingival-occlusal / incisal direction may also be referred to as the vertical direction;

[0012] Mandibular - toward the lower jaw;

[0013] Maxillary - toward the upper jaw.

[0014] Upright - inclination of the root of a tooth in mesial-distal direction.

[0015] It has been known to provide orthodontic brackets having at least one mesial-distally extending tunnel or archwire slot. Such known brackets may have a labial-buccally opening archwire slot which, when coacting with an archwire and there being selective forces applied between the archwire and bracket, will allow crown tipping movements. A problem with such brackets is that a ligature typically is required to retain the archwire in the labial-buccally opening archwire slot. A ligature is a small flexible band that wraps around tie wings or extensions on the bracket to hold the archwire in place. Ligatures can be made of elastomeric material, plastic or metal wire or bands.

[0016] The problems resulting from the use of ligatures have been addressed by self-ligating orthodontic brackets that eliminate the need to rely on ligatures for retaining an archwire in the archwire slot of the bracket. A self-ligating bracket is intended to eliminate any problem encountered in ligature failure, whether the ligature is of elastomeric, plastic or wire construction. Self-ligating brackets also diminish the undesired drag on an archwire, which is induced by a ligature. Self-ligating brackets typically have a moveable component that entraps an archwire in a slot in the bracket.PATENTAttorney Docket No. 7815-9028.01Summary

[0017] In one aspect, the present disclosure concerns an orthodontic bracket that is self-ligating. The self-ligating orthodontic bracket includes a body member having a front surface defining a reference plane and a rear surface for attachment to a tooth. The bracket including first and second projections extending forwardly from the front surface of the body member, with the first projection having an archwire slot surface on one side thereof and the second projection having an archwire slot surface on one side thereof. The respective archwire slot surfaces are vertically spaced from one another in opposed facing relation such that an archwire slot is defined by the archwire slot surfaces and a portion of the front surface of the body member that is intermediate the archwire slot surfaces.

[0018] A first channel is defined in the first projection and further includes a bed and opposed members having side walls extending forwardly and tabs extending from the side walls and toward each other mesially-distally with a gap therebetween, and a second channel is defined in the second projection and further includes a bed and opposed members having side walls extending forwardly and tabs extending from the side walls toward each other mesially-distally with a gap there between. The beds of the respective first and second channels in the first and second projections are aligned with one another in a common plane which is parallel to and spaced from the front surface of the body member.

[0019] A door is disposed in at least the first channel between the opposed side walls and between the bed and tabs thereof. The door is movable between an open position and a closed position, such that when the door is in the open position the doorPATENTAttorney Docket No. 7815-9028.01 is spaced from the second channel and provides access to and from the archwire slot, and when the door is in the closed position it is disposed in both the first and second channels between the respective beds and tabs thereof and prevents access to and from the archwire slot.

[0020] The bracket further includes a bore extending through the bed of the first projection, and a pin fixed in the bore and having a portion of the pin extending from the bore and disposed in the first channel. The door further includes a retention channel formed on a lingual side of the door, with the portion of the pin disposed in the first channel being received by the retention channel on the door, wherein when the door is moved to the open position, the portion of the pin disposed in the first channel engages a closed end of the retention channel which prevents removal of the door from the bracket, and wherein when the door is moved to the closed position the door is retained in the closed position due to friction between at least the door and the first and second channels.

[0021] The orthodontic bracket of the present disclosure is further characterized in that the bracket may further include a bonding base having front and rear surfaces. The body member rear surface may be attached to the front surface of the boding base and the body member may extend forwardly therefrom, with the rear surface of the bonding base being adapted for attachment to a crown of a tooth, and wherein the rear surface of the body member defines a torque angle with respect to the reference plane. The bracket may further include an auxiliary slot defined by a tunnel through the body member located between the front surface of the bonding base and the front surface of the body member.PATENTAttorney Docket No. 7815-9028.01

[0022] In addition, the body member, pin and door, need not be flexible or bendable. As such, it will be appreciated that the respective components may be constructed of any of a variety of rigid or semi-rigid materials. This advantageously permits featuring improved aesthetics, such as may be achieved by using ceramic type materials, which may be matched to the color of a patient’s teeth, or the components may be constructed of other materials, such as metals, plastics or the like.Brief Description of the Drawings

[0023] FIG. 1 is an exploded front perspective view of an orthodontic bracket of the present disclosure having a movable door and retention pin exploded from the body of the bracket.

[0024] FIG. 2 is a perspective view of the bracket of FIG. 1 when assembled, further having a mounting base and with the movable door in a closed position.

[0025] FIG. 3 is a perspective view of the bracket of FIG. 2 with the movable door in an open position.

[0026] FIG. 4 is a front elevation view of the bracket of FIG. 2.

[0027] FIG. 5 is a left side elevation view of the bracket of FIG. 2.

[0028] FIG. 6 is a lower rear perspective view of the bracket of FIG. 2 with the movable door removed for ease of viewing other features.

[0029] FIG. 7 is an exploded lower front perspective view of the bracket of FIG. 2 with the movable door and retention pin exploded from the body of the bracket.PATENTAttorney Docket No. 7815-9028.01Detailed Description of the Embodiments

[0030] The present disclosure is directed to a self-ligating orthodontic bracket for connecting one or more archwires to a tooth. An example embodiment of the selfligating orthodontic bracket 10 is shown generally in FIGS. 1 -7. The bracket 10 includes a body member 18 having a front surface 20 defining a reference plane RP and a rear surface 21 for attachment to a tooth and which defines a further reference plane RP1 , indicated in FIG. 5.

[0031] The rear surface 21 of the body member 18 defining the further reference surface RP1 provides a torque angle T with respect to an imaginary plane parallel to the reference plane RP. In this example the torque angle T is approximately 16° but an alternative angle may be incorporated into the bracket 10, as needed for the specific desired treatment.

[0032] It will be appreciated that the bracket 10 may be attached directly to a tooth or may further include a bonding base 12 having front and rear surfaces 14, 16, respectively, and the body member rear surface 21 may be attached to the front surface 14 of the bonding base 12, with the body member 18 extending forwardly therefrom. The bonding base 12 may be a plate-like member with the rear surface 16 being adapted for attachment to a crown of a tooth. As such, the bonding base 12 usually is not flat and instead the front surface 14 is slightly convex, with a corresponding slightly concave rear surface 16 adapted for bonding to a tooth when in use.

[0033] The bracket 10 includes first and second projections 22, 24 extending forwardly from the front surface 20 of the body member 18, with the first projection 22 having an archwire slot surface 26 on one side thereof and the second projection 24PATENTAttorney Docket No. 7815-9028.01 having an archwire slot surface 28 on one side thereof. The respective archwire slot surfaces 26, 28 are vertically spaced from one another in opposed facing relation such that an archwire slot 30 is defined by the archwire slot surfaces 26, 28 and a portion of the front surface 20 of the body member 18 that is intermediate the archwire slot surfaces 26, 28.

[0034] A first channel 32 is defined in the first projection 22 and further includes a bed 34 and opposed members 36, 38 having side walls 40, 42 extending forwardly and tabs 44, 46 extending from the side walls 40, 42 and toward each other mesially-distally with a gap therebetween, as shown in FIG. 1 . A second channel 52 is defined in the second projection 24 and further includes a bed 54 and opposed members 56, 58 having side walls 60, 62 extending forwardly and tabs 64, 66 extending from the side walls 60, 62 toward each other mesially-distally with a gap there between, as shown in FIG. 7. The beds 34, 54 of the respective first and second channels 32, 52 in the first and second projections 22, 24 are aligned with one another in a common plane RP2 which is parallel to and spaced from the front surface 20 of the body member 18, as shown in FIG. 1 .

[0035] A door 68 is disposed in at least the first channel 32 between the opposed side walls 40, 42 and between the bed 34 and tabs 44, 46 thereof. The door 68 is movable between an open position, shown in FIG. 3, and a closed position, shown in FIGS. 2 and 4-5, such that when the door 68 is in the open position the door 68 is spaced from the second channel 52 and provides access to and from the archwire slot 30, and when the door 68 is in the closed position it is disposed in both the first andPATENTAttorney Docket No. 7815-9028.01 second channels 32, 52 between the respective beds 34, 54 and tabs thereof and prevents access to and from the archwire slot 30.

[0036] The bracket 10 further includes a bore 70 extending through the bed 34 of the first projection 22, as shown in FIGS. 1 , 2, 6 and 7, and a pin 72, shown in FIGS. 1 ,2, 6 and 7. As shown in FIGS. 2 and 6 (when assembled), the pin 72 is fixed in the bore 70 and a portion of the pin 72 extends from the bore 70 and is disposed in the first channel 32. The door 68 further includes a retention channel 74 (shown in phantom lines in FIG. 7) formed on a lingual side 76 of the door 68. The portion of the pin 72 disposed in the first channel 32 is received by the retention channel 74 on the door 68, as shown in FIG. 2. When the door 68 is moved to the open position, as shown in FIG.3, the portion of the pin 72 disposed in the first channel 32 engages a closed end 78 (shown in FIG. 7) of the retention channel 74 which prevents removal of the door 68 from the bracket 10, and when the door 68 is moved to the closed position, as shown in FIGS. 2, 4 and 5, the door is retained in the closed position due to friction between at least the door 68 and the first and second channels 32, 52.

[0037] It will be appreciated that each of the first and second projections 22, 24 of the self-ligating orthodontic bracket 10 further includes respective tie wings 80, 82, as shown in FIGS. 2 and 5. While use of the door 68 would be preferred, use of ligatures and the tie wings 80, 82 may be used to supplement treatment of a patient, if it is determined that such optional use would be beneficial.

[0038] As shown in FIG. 3, when the door 68 of the self-ligating orthodontic bracket 10 is in the open position, the door 68 is trapped in the first channel 32 between the bed 34 of the first projection 22 and the opposed side walls 40, 42 extendingPATENTAttorney Docket No. 7815-9028.01 forwardly and the tabs 44, 46 extending from the side walls 40, 42 and toward each other mesial ly-distal ly. The door 68 is inserted into the first channel 32 prior to fixing the pin 72 in the bore 70 extending through the bed 34 of the first projection 22 so as to have the portion of the pin 72 extending from the bore 70 be disposed in the first channel 32 and in the retention channel 74 on the lingual side 76 of the door 68. The pin 72 prevents the door 68 from being removed from the first channel 32 and retains the door 68 in the first channel 32 when in an open position shown in FIG. 3.

[0039] The bore 70 extending through the bed 34 of the first projection 22 extends perpendicular to the front surface 20 of the body member 18. As shown in FIG. 1 , the door 68 further includes a raised rib 84 on a front surface 86 of the door 68. The raised rib 84 extends into the gap between the tabs 44, 46 of the first channel 32 in the first projection 22 when the door 68 is in the open position shown in FIG. 3. The raised rib 84 on the front surface 86 of the door 68 further extends into the gap between the tabs 64, 66 of the second channel 52 in the second projection 24 when the door is in the closed position, as shown in FIGS. 2 and 4. When the door 68 is moved to a closed position shown in FIGS. 2 and 4, the door 68 is further retained in the closed position due in part to friction between the raised rib 84 on the front surface 86 of the door 68 and the tabs 44, 46 and 64, 66 of the first and second channels, respectively. With the self-ligating orthodontic bracket 10, when an archwire is used to extend through the archwire slot 30 and to align the bracket 10, contact between the archwire and the lingual side 76 of the door 68 provides further friction that assists in retaining the door 68 in the closed position.

[0040] The body member 18 of the self-ligating orthodontic bracket 10 furtherPATENTAttorney Docket No. 7815-9028.01 includes a generally vertically extending auxiliary slot 90 through the body member 18, as shown in FIGS. 3 and 7. The auxiliary slot 90 is defined by a tunnel through the body member 18 located between the front surface 14 of the bonding base 12 and the front surface 20 of the body member 18.

[0041] In the self-ligating orthodontic bracket 10, upper ends of the tabs 64, 66 of the second channel 52 in the second projection 24 have opposed angled surfaces 92, 94 that define a V-shaped groove 96 narrowing in a direction toward the door 68, as shown in FIGS. 3 and 4. An upper end 98 of the door 68 includes a notch 100 aligned with the V-shaped groove 96 in the second projection 24.

[0042] Another key benefit the movable door offers is a solid positive surface for the archwire to press against creating a “tube” for structure and offering more torqueing to fully appreciate the prescription built into the bracket. Elastomeric ligatures may lose their elasticity after several hours and may take a set that limits the energy to hold the archwire against the bracket archwire slot, thereby becoming passive in moving the tooth to the desired final position. An elastomeric ligature must be replaced and for a short time the new ligature offers the energy to begin moving the tooth. Then, elasticity may again stop and the ligature may take a set. With the bracket of the present disclosure the lingual side 76 of the door 68 offers a surface against which an archwire may push, thereby moving the tooth into the final prescribed position built into the bracket. The pressure of an archwire against the lingual side 76 of the door 68 also provides additional friction, which assists in maintaining the door 68 in the closed position.PATENTAttorney Docket No. 7815-9028.01

[0043] The advantage of the door 68 also can be appreciated as follows. Suppose a particular tooth is misaligned lingually and to obtain the proper position the tooth needs to be torqued in a buccal / labial direction. An archwire may be disposed in an archwire slot such that the archwire tends to torque the tooth in the desired forward, buccal / labial direction. A bracket without a door would have the archwire slot open to the front, so there would be no structure for the archwire to press against in the forward direction. This would cause the archwire to tend to pop out of the open slot. As mentioned, elastic ligatures will provide some resistance to the archwire coming out of the slot, but such resistance by an elastomeric ligature is quite temporary. In constrast, the interior or lingual surface 76 of the closed movable door 68 provides a solid surface against which an archwire can press, urging the tooth to the desired position.

[0044] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the invention disclosed herein. For example, while the base is shown herein as having basically a single thickness, the base could have multiple layers forming a stepped configuration. That is, there may be a bottom layer or pad whose rear surface will attach to the crown of a tooth plus a smaller outer layer or pad on the front of the bottom layer but having a smaller perimeter than the bottom layer. The body member is attached to the outer layer of the base and the auxiliary archwire slot is bounded on the rear edge by the front surface of the outer layer of the base. Such an outer layer or pad on the front surface of a bottom layer may still be considered part of the base.

Claims

PATENTAttorney Docket No. 7815-9028.01Claims:1 . A self-ligating orthodontic bracket, comprising: a body member having a front surface defining a reference plane and a rear surface for attachment to a tooth; first and second projections extending forwardly from the front surface of the body member, the first projection having an archwire slot surface on one side thereof and the second projection having an archwire slot surface on one side thereof, the respective archwire slot surfaces being vertically spaced from one another in opposed facing relation such that an archwire slot is defined by the archwire slot surfaces and a portion of the front surface of the body member that is intermediate the archwire slot surfaces; a first channel defined in the first projection and further comprising a bed and opposed members having side walls extending forwardly and tabs extending from the side walls and toward each other mesially-distal ly with a gap therebetween, and a second channel defined in the second projection and further comprising a bed and opposed members having side walls extending forwardly and tabs extending from the side walls toward each other mesially-distally with a gap there between, the beds of the respective first and second channels in the first and second projections being aligned with one another in a common plane which is parallel to and spaced from the front surface of the body member; a door disposed in at least the first channel between the opposed side walls and between the bed and tabs thereof, the door being movable between an open position and a closed position, such that when the door is in the open position the door isPATENTAttorney Docket No. 7815-9028.01 spaced from the second channel and provides access to and from the archwire slot, and when the door is in the closed position it is disposed in both the first and second channels between the respective beds and tabs thereof and prevents access to and from the archwire slot; a bore extending through the bed of the first projection, and a pin fixed in the bore and having a portion of the pin extending from the bore and disposed in the first channel; the door further comprising a retention channel formed on a lingual side of the door, with the portion of the pin disposed in the first channel being received by the retention channel on the door; wherein when the door is moved to the open position, the portion of the pin disposed in the first channel engages a closed end of the retention channel which prevents removal of the door from the bracket; and wherein when the door is moved to the closed position the door is retained in the closed position due to friction between the door and the first and second channels.

2. The self-ligating orthodontic bracket of claim 1 wherein each of the first and second projections further comprises respective tie wings.

3. The self-ligating orthodontic bracket of claim 1 wherein when the door is in the open position, the door is trapped in the first channel between the bed of the first projection and the opposed side walls extending forwardly and the tabs extending from the side walls and toward each other mesially-distally.

4. The self-ligating orthodontic bracket of claim 1 wherein the door is inserted into the first channel prior to fixing the pin in the bore extending through the bed of the firstPATENTAttorney Docket No. 7815-9028.01 projection so as to have the portion of the pin extending from the bore be disposed in the first channel and in the retention channel on the lingual side of the door.

5. The self-ligating orthodontic bracket of claim 1 wherein the pin prevents the door from being removed from the first channel and retains the door in the first channel when in an open position.

6. The self-ligating orthodontic bracket of claim 1 wherein the bore extending through the bed of the first projection extends perpendicular to the front surface of the body member.

7. The self-ligating orthodontic bracket of claim 1 wherein the door further comprises a raised rib on a front surface of the door, which extends into the gap between the tabs of the first channel in the first projection when the door in the open position.

8. The self-ligating orthodontic bracket of claim 7 wherein the raised rib on the front surface of the door further extends into the gap between the tabs of the second channel in the second projection when the door is in the closed position.

9. The self-ligating orthodontic bracket of claim 8 wherein when the door is moved to a closed position the door is further retained in the closed position due in part to friction between the raised rib on the front surface of the door and the tabs of the first and second channels.

10. The self-ligating orthodontic bracket of claim 1 wherein when an archwire is used to extend through the archwire slot and to align the bracket, contact between the archwire and the lingual side of the door provides further friction that assists in retaining the door in the closed position.PATENTAttorney Docket No. 7815-9028.011 1 . The self-ligating orthodontic bracket of claim 1 wherein the body member further includes a generally vertically extending auxiliary slot through the body member.

12. The self-ligating orthodontic bracket of claim 11 wherein the auxiliary slot is defined by a tunnel through the body member located between the front and rear surfaces of the body member.

13. The self-ligating orthodontic bracket of claim 1 wherein upper ends of the tabs of the second channel in the second projection have opposed angled surfaces that define a V-shaped groove narrowing in a direction toward the door.

14. The self-ligating orthodontic bracket of claim 13 wherein an upper end of the door further comprises a notch aligned with the V-shaped groove in the second projection.

15. The self-ligating orthodontic bracket of claim 1 further comprising a bonding base having front and rear surfaces, the body member rear surface attached to the front surface of the boding base with the body member extending forwardly therefrom, and the rear surface of the bonding base being adapted for attachment to a crown of a tooth, wherein the rear surface of the body member defines a torque angle with respect to the reference plane.

16. The self-ligating orthodontic bracket of claim 15 wherein an auxiliary slot is defined by a tunnel through the body member located between the front surface of the bonding base and the front surface of the body member.

Images