Systems, methods, and devices for improved orthodontic treatment of a patient's teeth are provided herein. In some aspects, a method for fabricating an orthodontic appliance for treating a patient's teeth is disclosed. The method may comprise determining a movement path to move a tooth from an initial arrangement towards a target arrangement; determining a force system to move the tooth along the movement path; determining a variable gable bend to produce the force system; determining a geometry for a tooth receiving cavity of the appliance based on the variable gable bend; and generating instructions for fabricating the appliance having a tooth receiving cavity formed according to the geometry for the tooth receiving cavity.