Self-ligating orthodontic bracket
Appliances and related methods use a resilient retention member that is retained in a recess within a body that is optionally made from a suitably translucent ceramic material. The retention member, optionally in combination with one or more side walls of the recess, provides two or more regions for accommodating a protrusion. The protrusion, in turn, is part of a sliding door which can be opened or closed depending on the equilibrium position of the protrusion with respect to the two or more regions. Based on the engagement between the protrusion and the retention member, these appliances can provide discrete opened and closed door positions to facilitate archwire ligation.
1. An orthodontic appliance comprising:
a base;
a body extending outwardly from the base;
an archwire slot extending across the body in a generally mesial-distal direction;
a recess located on the body adjacent the archwire slot;
a retention member received in the recess, the retention member dividing the recess into at least first and second regions, wherein the retention member comprises a first beam extending along a mesial distal direction; and
a door slidably engaged to the body and having a first protrusion, wherein the first protrusion comprises a generally trapezoidal profile as viewed from the mesial or distal direction, the first protrusion having a gingival-facing edge forming a first sidewall angle β 1 and an occlusal-facing edge forming a second side-wall angle β 2 , the first protrusion extending into the first region when the door is open to allow access to the archwire slot and extending into the second region when the door is closed to prevent access to the archwire slot.
2. The appliance of claim 1 , wherein the recess has a bottom wall and opposing first and second side walls.
3. The appliance of claim 1 , wherein the first beam has a curved configuration along some or all of its length.
4. The appliance of claim 1 , wherein the first beam is a round beam.
5. The appliance of claim 1 , wherein the first beam is a rectangular beam.
6. The appliance of claim 5 , wherein the rectangular beam extends along an axis oriented at an angle θ relative to the sliding direction the door, wherein the angle θ is at least about 0.1 degrees.
7. The appliance of claim 6 , wherein the angle θ is about 90 degrees or less.
8. The appliance of claim 1 , further comprising a second beam spaced apart from the first beam along a generally occlusal-gingival direction, wherein each beam extends along a generally mesial-distal direction, the first region is located between the first and second beams, and the second region is located on the occlusal or gingival side of both the first and second beams.
9. The appliance of claim 8 , wherein the first beam has a generally rectangular cross-section and the second beam has a generally circular cross-section.
10. The appliance of claim 9 , wherein the rectangular beam extends along an axis oriented at an angle θ relative to the sliding direction the door, wherein the angle θ is at least about 0.1 degrees.
11. The appliance of claim 10 , wherein the angle θ is about 90 degrees or less.
12. The appliance of claim 9 , wherein the second beam is spaced from the first beam toward the gingival direction.
13. The appliance of claim 12 , wherein first side wall angle β 1 is less than the second sidewall angle β 2 .
14. The appliance of claim 1 , wherein the first beam comprises a superelastic nickel-titanium alloy.
15. The appliance of claim 1 , wherein the generally trapezoidal profile is an asymmetric trapezoidal profile.
16. The appliance of claim 1 , further comprising a second protrusion spaced from the first protrusion along the sliding direction of the door, whereby the first and second protrusions reside in respective second and first regions when the door is open and the first and second protrusions both reside in the second region when the door is closed.