Automatic placement of precision cuts
An orthodontic positioning device and methods for making an orthodontic positioning device including a first patient removable orthodontic tooth positioning appliance having teeth receiving cavities shaped to receive and apply a resilient positioning force to a patient's teeth provided in one of an upper jaw and a lower jaw. The first appliance includes a hook configured to receive an orthodontic elastic band. The orthodontic positioning device also includes a second patient removable orthodontic tooth positioning appliance having teeth receiving cavities shaped to receive and apply a resilient positioning force to a patient's teeth provided in the other of the upper jaw and the lower jaw. The second appliance includes a cutout operable to expose an orthodontic elastic band receiving member.
1. A computer-implemented method of trimming an orthodontic positioning appliance having teeth receiving cavities, the method comprising:
receiving material including a portion having the shape of an orthodontic positioning appliance having teeth receiving cavities;
receiving a digital representation of trimming instructions, the trimming instructions including an elastic band receiving member cutout line or a hook cutout line, wherein the elastic band receiving member cutout line or the hook cutout line defines a gingival-facing surface of the orthodontic positioning appliance; and
cutting the material along the elastic band receiving member cutout line or the hook cutout line with a cutting element.
2. The method of claim 1 , wherein cutting the material includes:
arranging the material over a mold shaped to receive the orthodontic positioning appliance;
applying a cutting element along a direction normal to a buccal surface or a labial surface of the teeth receiving cavities; and
retracting the cutting element from the mold if the cutting element contacts a surface of the mold.
3. The method of claim 1 , wherein the trimming instructions include the elastic band receiving member cutout line and wherein the elastic band receiving member cutout line is shaped to accommodate an elastic band receiving member disposed on a tooth.
4. The method of claim 3 , wherein the elastic band receiving member comprises an orthodontic button or a temporary anchorage device.
5. The method of claim 3 , wherein the elastic band receiving member cutout line is shaped to avoid interference with the elastic band receiving member.
6. The method of claim 3 , wherein the elastic band receiving member cutout line is positioned so as to define a distance between an edge of the elastic band receiving member and a portion of the elastic band receiving member cutout line.
7. The method of claim 3 , wherein the elastic band receiving member cutout line is shaped to conform to at least a portion of the elastic band receiving member.
8. The method of claim 3 , wherein the elastic band receiving member cutout line comprises a curved shape.
9. The method of claim 3 , wherein the elastic band receiving member cutout line protrudes into the gingival-facing surface of the orthodontic positioning appliance a distance at least halfway between a gingival line and an occlusal surface of a tooth when the orthodontic positioning appliance is worn on a patient's teeth.
10. The method of claim 1 , wherein the trimming instructions include the hook cutout line and wherein the hook cutout line is shaped to define a hook in the orthodontic positioning appliance.
11. The method of claim 10 , wherein the hook is shaped to receive an elastic band.
12. The method of claim 10 , wherein the hook is shaped to follow a contour of a patient's teeth.
13. The method of claim 10 , wherein the hook is shaped to reduce contact or interference with tissue on an inner surface of the patient's mouth.
14. The method of claim 10 , wherein the hook cutout line is shaped to extend towards an elastic band receiving member disposed on a tooth when the orthodontic positioning appliance is worn on a patient's teeth.
15. The method of claim 1 , wherein the elastic band receiving member or the hook cutout line is disposed over a facial surface of a tooth when the orthodontic positioning appliance is worn on a patient's teeth.
16. The method of claim 1 , wherein the material comprises a polymer material.
17. The method of claim 1 , wherein the portion of the material having the shape of the orthodontic positioning appliance is fabricated by thermal forming.
18. The method of claim 1 , wherein the portion of the material having the shape of the orthodontic positioning appliance is fabricated by direct fabrication.
19. The method of claim 1 , wherein the orthodontic positioning appliance is shaped to treat a Class I type malocclusion, a Class II type malocclusion, or a Class III type malocclusion.
20. The method of claim 1 , wherein the teeth receiving cavities are shaped to reposition a patient's teeth from an initial tooth arrangement towards a target tooth arrangement.