3D printed dental appliances with variable thickness regions

A dental appliance system comprising:

• a first dental appliance comprising a first plurality of 3D printed polymer layers, wherein the first plurality of 3D printed polymer layers comprises a first plurality of sequentially polymerized appliance cross-sections;
• and
• a second dental appliance comprising:
• a second plurality of 3D printed polymer layers, wherein the second plurality of 3D printed polymer layers comprises a second plurality of sequentially polymerized appliance cross-sections, and
• an appliance shell formed from the second plurality of sequentially polymerized appliance cross-sections, wherein the appliance shell comprises:
• a plurality of tooth receiving cavities formed from the second plurality of sequentially polymerized appliance cross-sections, the plurality of tooth receiving cavities arranged to receive a dentition and to exert one or more forces on the dentition, and
• a plurality of variable thickness regions formed from the second plurality of sequentially polymerized appliance cross-sections, wherein the plurality of variable thickness regions comprises a corresponding plurality of different appliance thicknesses, wherein the plurality of variable thickness regions are arranged to implement one or more treatment outcomes, and wherein the plurality of variable thickness regions comprise a thickened mesial region positioned near a top of a tooth crown and a thickened distal region positioned near a bottom of the tooth crown, the thickened mesial region and the thickened distal region being integrally formed with the appliance shell as a single monolithic component.