Method and system for optimizing dental aligner geometry

Abstract

Method and system for establishing an initial position of a tooth, determining a target position of the tooth in a treatment plan, calculating a movement vector associated with the tooth movement from the initial position to the target position, determining a plurality of components corresponding to the movement vector, and determining a corresponding one or more positions of a respective one or more attachment devices relative to a surface plane of the tooth such that the one or more attachment devices engages with a dental appliance are provided.

What is claimed is: 
     
         1 . A method for designing an orthodontic aligner, the method comprising:
 receiving a digital scan of a patient's dentition, wherein the digital scan provides a three-dimensional digital representation of at least one tooth of the patient's dentition;   determining, as part of an orthodontic treatment plan, a plurality of treatment stages to incrementally reposition the at least one tooth of the patient's dentition from an initial position to a target position;   determining, for one of the plurality of treatment stages, a movement trajectory for the at least one tooth from a first position to a second position as part of the orthodontic treatment plan;   determining a plurality of contact points between the orthodontic aligner and a surface of the at least one tooth of the patient's dentition;   determining individual trajectories from the first position to the second position for each of the plurality of contact points; and   designing a geometry for the orthodontic aligner based at least in part on the individual trajectories determine for each of the plurality of contact points.   
     
     
         2 . The method of  claim 1 , wherein at least one of the plurality of contact points corresponds to a ridge, protrusion, or dimple on the orthodontic aligner. 
     
     
         3 . The method of  claim 1 , wherein designing the geometry of the orthodontic aligner comprises incorporating a ridge, protrusion, or dimple into the geometry of the orthodontic aligner. 
     
     
         4 . The method of  claim 3 , wherein the ridge, protrusion, or dimple is incorporated at one of the plurality of contact points to modify a corresponding individual trajectory of the one of the plurality contact points. 
     
     
         5 . The method of  claim 1 , wherein at least one of the plurality of contact points corresponds to a crown point on the at least one tooth of the patient's dentition. 
     
     
         6 . The method of  claim 1 , further comprising determining a force system for moving the at least one tooth from the first position to the second position. 
     
     
         7 . The method of  claim 6 , wherein the geometry of the orthodontic aligner is designed such that contact between the orthodontic aligner and the surface of the at least one tooth of the patient's dentition at the plurality of contact points provides the determined force system. 
     
     
         8 . The method of  claim 1 , wherein the geometry of the orthodontic aligner is designed to reduce friction between an inner surface of the orthodontic align and the surface of the at least one tooth of the patient's dentition. 
     
     
         9 . The method of  claim 1 , further comprising determining active surfaces on the at least one tooth of the patient's dentition, wherein the active surfaces comprise surfaces onto which forces may be applied to move the at least one tooth along the determined movement trajectory. 
     
     
         10 . The method of  claim 9 , wherein determining active surfaces comprises identifying surfaces with desirable orientations for imparting a force system for moving the at least one tooth from the first position to the second position. 
     
     
         11 . The method of  claim 9 , further comprising determining resistive surfaces on the at least one tooth of the patient's dentition. 
     
     
         12 . The method of  claim 11 , further comprising
 determining a ratio of the active surfaces to the resistive surfaces; and   comparing the ratio to a predefined threshold to assess whether the at least one tooth has adequate active tooth surface for receiving a force system for moving the at least one tooth from the first position to the second position.   
     
     
         13 . The method of  claim 1 , wherein determining the plurality of contact points comprises assessing which areas of the surface of the at least one tooth are accessible intraorally. 
     
     
         14 . The method of  claim 1 , further comprising tracking movement of the plurality of contact points throughout the orthodontic treatment plan. 
     
     
         15 . The method of  claim 1 , wherein geometry for the orthodontic aligner comprises non-uniform thickness. 
     
     
         16 . The method of  claim 1 , further comprising determining whether a dental attachment is needed to impart a force system for moving the at least one tooth along the movement trajectory from the first position to the second position. 
     
     
         17 . The method of  claim 1 , further comprising contouring a model of a tooth surface of the at least one tooth to improve an amount of surface for receiving a force system for moving the at least one tooth from the first position to the second position. 
     
     
         18 . The method of  claim 1 , further comprising manufacturing the orthodontic aligner; wherein manufacturing the orthodontic aligner comprises pressure fitting polymeric material over a positive physical dental model corresponding to the one of the plurality of treatment stages. 
     
     
         19 . The method of  claim 1 , further comprising manufacturing the orthodontic aligner; wherein manufacturing the orthodontic aligner comprises forming the geometry of the orthodontic aligner through stereolithography. 
     
     
         20 . A non-transitory computing device readable medium storing instructions executable by a processor to cause a computing device to perform a method, the method comprising:
 receiving a digital scan of a patient's dentition, wherein the digital scan provides a three-dimensional digital representation of at least one tooth of the patient's dentition;   determining, as part of an orthodontic treatment plan, a plurality of treatment stages to incrementally reposition the at least one tooth of the patient's dentition from an initial position to a target position;   determining, for one of the plurality of treatment stages, a movement trajectory for the at least one tooth from a first position to a second position as part of the orthodontic treatment plan;   determining a plurality of contact points between the orthodontic aligner and a surface of the at least one tooth of the patient's dentition;   determining individual trajectories from the first position to the second position for each of the plurality of contact points; and   designing a geometry for the orthodontic aligner based at least in part on the individual trajectories determine for each of the plurality of contact points.