Systems and method for fabrication of dental appliances are provided. An example method includes receiving data identifying approximate locations of individual teeth in a three-dimensional digital dental model representing an impressioned position of a patient's dentition. The example method may also include generating component models corresponding to individual teeth for each of the identified approximate locations. The component models may be disposed at initial positions based on the impressioned position of the patient's dentition. The example method also includes determining target positions for the component models and generating a tooth-positioning appliance design based on the determined target positions for the component models. The method may also include causing a tooth-positioning appliance to be fabricated based on the tooth-positioning appliance design.