Orthodontic appliances with elastic segments

Abstract

Improved orthodontic appliances, along with related systems and methods, are provided. In one aspect, an orthodontic appliance is provided. The appliance includes a plurality of discrete shell segments, each including one or more cavities shaped to receive at least portions of teeth. The discrete shell segments are joined by an elastic material to form a single appliance shell.

1 . (canceled) 
     
     
         2 . An orthodontic appliance comprising:
 an appliance shell configured to reposition a patient's teeth from a first arrangement toward a second arrangement, the appliance shell comprising:
 a plurality of shell segments, wherein each shell segment comprises a first elastic modulus, and wherein each shell segment comprises one or more tooth-receiving cavities, and 
 a plurality of elastic segments, wherein each elastic segment comprises a second elastic modulus less than the first elastic modulus, 
 wherein each elastic segment is coupled to a respective pair of adjacent shell segments, such that when the appliance shell is worn on the patient's teeth, each elastic segment is stretched to increase a spacing between the respective pair of adjacent shell segments, and each elastic segment resists the stretching to apply a repositioning force to teeth received by the respective pair of adjacent shell segments. 
   
     
     
         3 . The orthodontic appliance of  claim 2 , wherein each elastic segment is located at an interproximal region of the appliance shell and continuously spans an occlusal, buccal, and lingual surface of the interproximal region. 
     
     
         4 . The orthodontic appliance of  claim 2 , wherein the stretching of each elastic segment increases an interproximal spacing between the respective pair of adjacent shell segments. 
     
     
         5 . The orthodontic appliance of  claim 2 , wherein each shell segment comprises a first material having the first elastic modulus, and each elastic segment comprises a second material having the second elastic modulus. 
     
     
         6 . The orthodontic appliance of  claim 5 , wherein the first material is different from the second material. 
     
     
         7 . The orthodontic appliance of  claim 2 , wherein at least some of the plurality of shell segments are configured to receive a single tooth. 
     
     
         8 . The orthodontic appliance of  claim 2 , wherein each elastic segment is directly coupled to the respective pair of adjacent shell segments. 
     
     
         9 . The orthodontic appliance of  claim 2 , wherein the plurality of elastic segments are a plurality of discrete elastic segments. 
     
     
         10 . The orthodontic appliance of  claim 2 , wherein the plurality of elastic segments are part of a material layer coating one or more surfaces of the appliance shell. 
     
     
         11 . The orthodontic appliance of  claim 2 , wherein at least some of the plurality of elastic segments include a pre-loading force before the appliance shell is placed on the patient's teeth. 
     
     
         12 . A method comprising:
 determining a treatment plan for a patient's teeth, the treatment plan comprising repositioning the patient's teeth from a first arrangement toward a second arrangement;   generating a digital model of an appliance shell configured to reposition the patient's teeth from the first arrangement toward the second arrangement, wherein the appliance shell comprises:
 a plurality of shell segments, wherein each shell segment comprises a first elastic modulus, and wherein each shell segment comprises one or more tooth-receiving cavities, and 
 a plurality of elastic segments, wherein each elastic segment comprises a second elastic modulus less than the first elastic modulus, 
 wherein each elastic segment is coupled to a respective pair of adjacent shell segments, such that when the appliance shell is worn on the patient's teeth, each elastic segment is stretched to increase a spacing between the respective pair of adjacent shell segments, and each elastic segment resists the stretching to apply a repositioning force to teeth received by the respective pair of adjacent shell segments; and 
   transmitting the digital model to a fabrication system, wherein the fabrication system is configured to fabricate the appliance shell based on the digital model.   
     
     
         13 . The method of  claim 12 , wherein each elastic segment is located at an interproximal region of the appliance shell and continuously spans an occlusal, buccal, and lingual surface of the interproximal region. 
     
     
         14 . The method of  claim 12 , wherein the stretching of each elastic segment increases an interproximal spacing between the respective pair of adjacent shell segments. 
     
     
         15 . The method of  claim 12 , wherein each shell segment comprises a first material having the first elastic modulus, and each elastic segment comprises a second material having the second elastic modulus. 
     
     
         16 . The method of  claim 15 , wherein the first material is different from the second material. 
     
     
         17 . The method of  claim 12 , wherein the fabrication system is configured to fabricate the appliance shell using a rapid prototyping process. 
     
     
         18 . The method of  claim 12 , further comprising fabricating the appliance shell based on the digital model. 
     
     
         19 . The method of  claim 12 , wherein each elastic segment is directly coupled to the respective pair of adjacent shell segments. 
     
     
         20 . The method of  claim 12 , wherein the plurality of elastic segments are a plurality of discrete elastic segments. 
     
     
         21 . The method of  claim 12 , wherein the plurality of elastic segments are part of a material layer coating one or more surfaces of the appliance shell.