Method for generating restarted orthodontic treatment plan

A computer-implemented method for generating restarted orthodontic treatment plan, comprising:

• obtaining a first group of M 3D digital models of teeth which respectively represent the last M successive tooth arrangements in a previous orthodontic treatment plan of a dentition;
• obtaining a first 3D digital model of teeth which represents the tooth arrangement of the dentition upon restart of orthodontic treatment;
• replacing at least one tooth model in the first group of 3D digital models of teeth with corresponding tooth model in the first 3D digital model of teeth, to obtain a second group of M 3D digital models of teeth;
• performing collision and gap optimization on the last one 3D digital model of teeth in the second group of 3D digital models of teeth to obtain a second 3D digital model of teeth representing a target tooth arrangement of a restarted orthodontic treatment plan;
• identifying a 3D digital model of teeth in the second group of 3D digital models of teeth, of which the tooth arrangement is closest to the first 3D digital model;
• calculating key frames of the restarted orthodontic treatment plan based on pose differences of teeth to be repositioned between the first 3D digital model of teeth and the identified 3D digital model of teeth, pose differences between the identified 3D digital model of teeth and corresponding key frames of the second group of 3D digital model of teeth, and pose differences of the teeth to be repositioned between the second 3D digital model of teeth and the last one of the second group of 3D digital models of teeth;
• interpolating based on the poses of the teeth to be repositioned of the corresponding key frames of the restarted orthodontic treatment plan, to obtain other steps of the restarted orthodontic treatment plan,
• wherein a key frame is a step in which any tooth starts or stops a movement, M is a natural number greater than 2, and an orthodontic treatment plan comprises a plurality of successive tooth arrangements from an initial tooth arrangement to a target tooth arrangement, and represents the path of orthodontic treatment;
• and
• fabricating a plurality of successive shell-shaped tooth repositioners based on corresponding successive steps of the restarted orthodontic treatment plan.