Systems and methods for fabrication of orthodontic aligners

A non-transitory computing device readable medium storing instructions executable by a processor to cause a computing device to perform a method, the method comprising:

• receiving an initial dentition model of a patient's teeth in an initial arrangement;
• determining a target arrangement for the patient's teeth;
• generating an orthodontic treatment plan, wherein the orthodontic treatment plan comprises a plurality of incremental arrangements to sequentially reposition the patient's teeth from the initial arrangement towards the target arrangement;
• determining, for at least one of the plurality of incremental arrangements, a geometry corresponding to a pair of orthodontic aligners, wherein the geometries for the pair of orthodontic aligners comprises:
• a first plurality of teeth-receiving cavities corresponding to an upper aligner, wherein the first plurality of teeth-receiving cavities are configured to receive at least a portion of the patient's upper dentition;
• a first marking disposed on the first plurality of teeth-receiving cavities, wherein the first marking corresponds to a position of a first hook for receiving a first end of an elastic band;
• a second plurality of teeth-receiving cavities corresponding to a lower aligner, wherein the second plurality of teeth-receiving cavities are configured to receive at least a portion of the patient's lower dentition;
• a second marking disposed on the second plurality of teeth-receiving cavities, wherein the second marking corresponds to a position of a second hook for receiving a second end of the elastic band;
• and
• fabricating the pair of orthodontic aligners based on the geometries determined, wherein fabricating the pair of orthodontic aligners comprises:
• forming the first plurality of teeth-receiving cavities;
• forming the first marking on the first plurality of teeth-receiving cavities;
• forming the second plurality of teeth-receiving cavities;
• and
• forming the second marking on the second plurality of teeth-receiving cavities;
• wherein the first hook extends in a gingival direction relative to a gingival edge of the geometry of the upper aligner.

A method of planning an orthodontic treatment, the method comprising:

• receiving an initial dentition model of a patient's teeth in an initial arrangement;
• determining a target arrangement for the patient's teeth;
• generating an orthodontic treatment plan, wherein the orthodontic treatment plan comprises a plurality of incremental arrangements to sequentially reposition the patient's teeth from the initial arrangement towards the target arrangement;
• determining, for at least one of the plurality of incremental arrangements, a geometry corresponding to an orthodontic aligner, wherein the geometry comprises:
• a plurality of teeth-receiving cavities configured to receive at least a portion of the patient's upper or lower dentition;
• and
• a marking disposed on the plurality of teeth-receiving cavities, wherein the marking corresponds to a position of a hook for receiving an end of an elastic band;
• fabricating the orthodontic aligner based on the geometry determined, wherein fabricating the orthodontic aligner comprises:
• forming the plurality of teeth-receiving cavities;
• forming the marking on the first plurality of teeth-receiving cavities;
• and
• forming the hook by cutting the plurality of teeth-receiving cavities based on the marking;
• wherein cutting the plurality of teeth-receiving cavities comprises manual cutting;
• wherein the hook extends in a gingival direction relative to a gingival edge of the geometry of the upper aligner.