Method and system for optimizing dental aligner geometry

1. A method for configuring one or more attachment devices for moving a tooth according to a treatment plan, the method comprising:

scanning, with a dental scanning apparatus, a portion of a patient's dentition to collect a digital scan, wherein the digital scan provides a digital representation of both a crown and root of the tooth;

receiving, at a processing unit, the digital scan of the tooth;

determining, using the processing unit, a first position and a second position of the tooth in the treatment plan, wherein the first position is based at least in part on the digital scan received by the processing unit;

calculating, using the processing unit, a movement vector from the first position to the second position;

simulating, using the processing unit, movement of the tooth from the first position to the second position to determine one or more force components to produce movement of the tooth from the first position to the second position along the movement vector;

arranging, using the processing unit, the one or more attachment devices to engage a polymeric shell of a dental appliance in order to apply the one or more force components onto the tooth to produce the movement of the tooth from the first position to the second position along the movement vector;

altering, using the processing unit, a shape of the one or more of the attachment devices to aid in applying the one or more force components onto the tooth;

determining active surfaces of the tooth and resistance surfaces of the tooth;

determining, using the active surfaces and the resistance surfaces, a geometry for a cavity of the polymeric shell of the dental appliance accommodating the movement of the tooth from the first position to the second position along the movement vector;

generating fabrication instructions for fabricating the dental appliance with the cavity of the dental appliance based on the determined geometry; and

transmitting the fabrication instructions to a fabrication machine.

2. The method of claim 1 , wherein the movement comprises rotational and translational movement of the tooth.

3. The method of claim 1 , further comprising determining whether the tooth comprises a sufficient amount of active surfaces onto which the one or more force components can be applied to produce the movement of the tooth, and wherein the configuration of the one or more attachment devices is determined in response to a determination that the amount of active surfaces is insufficient.

4. The method of claim 3 , wherein the determined configuration of the one or more attachment devices increases the amount of active surfaces of the tooth.

5. The method of claim 3 , wherein the determining whether the tooth comprises the sufficient amount of active surfaces comprises comparing the amount of active surfaces to an amount of resistance surfaces opposing the active surfaces.

6. The method of claim 5 , wherein the active surfaces comprise one or more crown surfaces and the resistance surfaces comprise one or more root surfaces.

7. The method of claim 1 , wherein the geometry of the cavity is determined based on a sweep geometry defined by a three-dimensional volume occupied by the tooth during the movement of the tooth from the first position to the second position.

8. The method of claim 1 , wherein the geometry of the cavity comprises a relief area shaped to reduce interference between the tooth and the dental appliance during the movement of the tooth from the first position to the second position.

9. The method of claim 1 , further comprising defining one or more contact points on the dental appliance that engage the tooth or the one or more attachment devices in order to produce the movement of the tooth from the first position to the second position.

10. The method of claim 1 , wherein the fabrication instructions are configured to fabricate the dental appliance using a rapid prototyping machine.