Methods and apparatus for making a polymeric orthodontic appliance

Patent metadata

Field	Value
Publication number	US-9259295-B2
Application number	US-201113225591-A
Country	US
Kind code	B2
Filing date	Sep 6, 2011
Priority date	Sep 9, 2010
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

A series of polymeric orthodontic appliances is made by providing a set of tooth analogs, each having a model crown that represents the shape of a corresponding tooth of the patient. The tooth analogs are moved along respective guides as needed in order to bring the associated model crown an incremental step toward or away from its desired position. The polymeric appliance is formed by placing a sheet of polymeric material over the model crowns after at least one tooth analog has been moved to create a desired model tooth arrangement.

First claim

The invention claimed is:

1. A method of making a polymeric orthodontic appliance comprising:
providing a set of physical tooth analogs each having a model tooth crown with a shape that is representative of the shape of a respective tooth crown in a patient's dental arch, the crown having labial and lingual exterior surfaces, and wherein the physical tooth analogs are arranged in an arch;
obtaining data for at least some of the tooth analogs that represents a path of movement for the corresponding model crown to a desired position;
using the data to construct a set of guides for guiding the movement of the tooth analogs in such a manner that the respective model crowns are moved along corresponding paths, wherein at least some of the guides comprise channels in a platform having a longitudinal axis and first and second closed ends, the axis arranged in directions that define at least a portion of the path of movement for the corresponding model crown, and wherein at least one of the channels extends to the second closed end in a direction away from the arch to define an arch exterior channel, the second end displaced in a labial direction from the labial surfaces of the corresponding model crown and the arch when the arch exterior channel extends at least partially in a labial direction and displaced in a lingual direction from the lingual surfaces of the corresponding model crown and the arch when the arch exterior channel extends at least partially in a lingual direction;
moving one or more of the tooth analogs along their respective channels as needed in order to bring the corresponding model crown an incremental step either toward or away from its desired position; and
forming the polymeric appliance over the model crowns after at least one of the tooth analogs has been moved.

2. The method of claim 1 wherein at least one guide includes a track, and wherein at least one tooth analog includes at least one leg that is received in the track.

3. The method of claim 2 , wherein the physical tooth analogs are arranged in an arch, wherein at least one guide includes at least three tracks, wherein at least one tooth analog includes at least three legs each having an outer end that is received in a respective track, and wherein one track is located outside the arch.

4. The method of claim 1 wherein each guide includes structure that hinders movement of the tooth analog in one direction along the guide.

5. The method of claim 4 wherein the structure comprises ratchet structure, the ratchet structure hindering movement within the channels.

6. The method of claim 5 wherein the ratchet structure includes a row of inclined ratchet teeth in contact with the tooth analog, and wherein the ratchet teeth are deformable to facilitate movement of the tooth analog in one direction and hinder movement of the tooth analog in an opposite direction.

7. The method of claim 6 , wherein the tooth analog comprises a base with a leg in contact with the channel, and wherein the row of ratchet teeth is connected to the channel and in contact with the leg.

8. The method of claim 1 wherein each tooth analog includes a base that is received in a pan containing a quantity of material, and wherein the quantity of material can change from a first state that facilitates movement of the base relative to the pan and to a second state that hinders movement of the base relative to the pan.

9. The method of claim 8 and including a heating element thermally connected to the pan, and including the act of activating the heating element in order to decrease the viscosity of the quantity of material.

10. The method of claim 1 wherein each channel comprises a first end and a second end opposite the first end, and wherein the model crown is in a position corresponding to the initial position of the patient's tooth when the tooth analog is located adjacent the first end of the channel.

11. The method of claim 1 wherein the model crown is in a position corresponding to the desired target position of the patient's tooth when the tooth analog is located adjacent the second end.

12. The method of claim 1 wherein at least one guide comprises an elongated slot, and wherein the tooth analog includes a base that extends through the slot.

13. The method of claim 12 wherein the base includes threads and wherein the tooth analog further includes a nut received on the threads for selectively securing the tooth analog in a fixed position relative to the guide.

14. The method of claim 13 wherein the base is elongated and is movable in directions along its longitudinal axis in order to change the height of the model crown.

15. The method of claim 12 wherein the tooth analog includes a cam lever pivotally connected to the base, and wherein the cam lever is operable to selectively secure the base in a fixed position relative to the guide.

16. The method of claim 1 , wherein at least one of the channels extends between the first and second closed ends along an inclined path in a vertical direction.

17. The method of claim 16 , and including a sleeve removably coupled to one of the bases, and wherein the method further includes the act of selecting the length of the sleeve for positioning the corresponding model crown at a desired height.

18. The method of claim 1 wherein at least one tooth analog remains in a stationary position as at least one of the remaining tooth analogs is moved.

19. The method of claim 1 and including the act of making the guides using a rapid prototyping process.

20. The method of claim 1 and including the acts of subsequently moving at least one tooth analog along its respective guide as needed in order to bring the model crowns into a subsequent crown arrangement and subsequently forming a second polymeric appliance over the model crowns.

21. The method of claim 1 wherein the act of moving one or more of the tooth analogs along its respective guide is carried out by pushing the one or more tooth analogs by hand.

Assignees

• Christoff James D
• Raby Richard E
• 3M Innovative Properties Co

Inventors

• Christoff James D
• Raby Richard E

Classifications

• A61C7/00

  Orthodontics, i.e. obtaining or maintaining the desired position of teeth, e.g. by straightening, evening, regulating, separating, or by correcting malocclusions · CPC title

• A61C7/08 Primary

  Mouthpiece-type retainers {or positioners, e.g. for both the lower and upper arch (arch-shaped medicament applicators for teeth or gums A61C19/063; mouthguards for protecting the teeth of sportsmen A63B71/085)} · CPC title