US Patent 10085823 Orthodontic repositioning appliances having improved geometry, methods and systems

The present invention provides methods and systems including orthodontic tooth positioning appliances. An exemplary appliance can include teeth receiving cavities shaped such that, when worn by a patient, repositioning the patient's teeth from a first arrangement toward a subsequent or target arrangement. Appliances can include a cavity having one or more shaped features or protrusions shaped and/or positioned so as to apply a desired force to a patient's tooth received in the cavity and move the tooth along a desired path or direction.