Shape engineered aligner - auto shaping

Abstract

The present invention relates to orthodontic positioning appliances and related methods. An appliance in accordance with the present invention has teeth receiving cavities shaped to receive and apply a resilient positioning force to the patient's teeth. At least one of the cavities of the appliance includes a portion shaped to compensate for non-elastic deformation due to use of the appliance.

1 . An orthodontic positioning appliance comprising:
 a patient removable orthodontic tooth positioning appliance having teeth receiving cavities shaped to receive and apply a resilient positioning force to the patient's teeth where at least one of the cavities includes a portion shaped to compensate for non-elastic deformation due to use of the appliance.   
   
   
       2 . The appliance of  claim 1 , wherein a width of a cavity is smaller than a corresponding width of the patient's teeth. 
   
   
       3 . The appliance of  claim 2 , wherein a width of a cavity is five percent to twenty percent smaller than a corresponding width of the patient's teeth. 
   
   
       4 . The appliance of  claim 3 , wherein a width of a cavity is ten percent to fifteen percent smaller than a corresponding width of the patient's teeth. 
   
   
       5 . The appliance of  claim 1 , wherein the portion of a cavity shaped to compensate for non-elastic deformation is adjacent to a cavity opening. 
   
   
       6 . The appliance of  claim 1 , wherein a plurality of the cavities are shaped to compensate for non-elastic deformation due to use of the appliance. 
   
   
       7 . The appliance of  claim 1 , wherein a cavity having a portion shaped to compensate for non-elastic deformation is a molar tooth receiving cavity. 
   
   
       8 . The appliance of  claim 1 , wherein a cavity having a portion shaped to compensate for non-elastic deformation is a bicuspid tooth receiving cavity. 
   
   
       9 . The appliance of  claim 1 , wherein the orthodontic positioning appliance comprises one or more teeth receiving cavities shaped to receive and resiliently reposition teeth from a first arrangement to a subsequent arrangement. 
   
   
       10 . The appliance of  claim 9 , wherein a cavity having a portion shaped to compensate for non-elastic deformation is shaped to receive and resiliently reposition a tooth from a first position to a second position. 
   
   
       11 . The appliance of  claim 9 , wherein a geometry of the shaped cavity portion is selected to apply a desired force or torque to a tooth when worn by the patient. 
   
   
       12 . The appliance of  claim 1 , wherein use of the appliance comprises positioning the appliance on the patient's teeth and removing the appliance from the patient's teeth. 
   
   
       13 . An improved orthodontic positioning appliance comprising a patient removable polymeric shell appliance having teeth receiving cavities shaped to receive the patient's teeth, wherein at least some of the teeth receiving cavities are shaped to receive and resiliently reposition the patient's teeth from a first arrangement toward a subsequent arrangement, the improvement comprising one or more teeth receiving cavities having a cavity portion shaped to compensate for non-elastic deformation due to use of the appliance. 
   
   
       14 . A method for fabricating an orthodontic positioning appliance having teeth receiving cavities, the method comprising:
 receiving a representation of a patient's teeth in a selected arrangement;   fabricating the appliance based on the received representation, the appliance comprising one or more teeth receiving cavities having a cavity portion shaped to compensate for non-elastic deformation due to use of the appliance.   
   
   
       15 . The method of  claim 14 , wherein the fabricating comprises creating a modified representation based on the received representation, the modified representation having at least one tooth with an exterior surface portion that is inwardly offset from a corresponding exterior surface in the received representation, and fabricating the appliance using the modified representation. 
   
   
       16 . The method of  claim 15 , wherein appliance fabrication comprises forming a polymeric sheet of material over a positive model based on the modified representation. 
   
   
       17 . A computer-implemented method for defining an orthodontic positioning appliance having teeth receiving cavities, the method comprising:
 receiving a digital representation of a patient's teeth in a selected arrangement;   modeling an appliance based on the received representation, the appliance comprising teeth receiving cavities wherein at least one of the cavities includes a portion shaped to compensate for non-elastic deformation due to use of the appliance.   
   
   
       18 . The method of  claim 17 , wherein the modeling includes defining teeth receiving cavities comprising:
 creating a modified representation from the received representation, the modified representation including at least one tooth with an exterior surface portion that is inwardly offset from a corresponding exterior surface in the received representation; and   defining teeth receiving cavities based on the modified representation.   
   
   
       19 . The method of  claim 17 , wherein the modeling includes defining teeth receiving cavities comprising:
 defining preliminary teeth receiving cavities based on the received representation; and   modifying at least one of the preliminary cavities to include a portion shaped to compensate for non-elastic deformation due to use of the appliance.   
   
   
       20 . The method of  claim 19 , wherein the modifying comprises reducing at least one preliminary cavity width by adding a portion shaped to compensate for non-elastic deformation due to use of the appliance. 
   
   
       21 . The method of  claim 17 , wherein the modeling includes defining exterior surfaces of the appliance based on a scaled representation of the patient's teeth.