Orthodontic aligners and methods of designing and fabricating orthodontic aligners based on tooth shape

A method of fabricating an orthodontic aligner of a series of orthodontic aligners for moving at least one tooth of a patient according to a treatment plan, the method comprising:

• receiving a first position of at least one tooth of a patient for a first treatment stage of a plurality of orthodontic treatment stages;
• determining a movement vector having a magnitude for moving the at least one tooth from a first position towards a second position in a mesial or distal direction;
• determining a first dental attachment profile of a first attachment, the first dental attachment profile associated with the movement vector and comprising a first dental attachment position and a first dental attachment angulation the first dental attachment position including a first vertical position relative to the at least one tooth of the first attachment, the first attachment being located on a buccal surface of the at least one tooth;
• determining a second vertical position relative to the at least one tooth of a second attachment, the second vertical position different than the first vertical position, the second attachment being located on the buccal surface of the at least one tooth;
• designing the orthodontic aligner having a shape based on the first dental attachment profile so that a physical orthodontic aligner having the shape, when in position on teeth of the patient at the first treatment stage, moves the at least one tooth from the first position towards the second position along the movement vector;
• and
• fabricating the physical orthodontic aligner.

A method of fabricating an orthodontic aligner of a series orthodontic aligners for moving at least one tooth of a patient according to a treatment plan, the method comprising:

• determining a first position of at least one tooth of a patient for a first treatment stage of plurality of orthodontic treatment stages and a second position of the at least one tooth;
• determining a movement vector for moving the at least one tooth from the first position towards the second position by determining trajectories of points of the at least one tooth from the first position towards the second position;
• analyzing a shape of a surface of a crown of the at least one tooth of the patient based on the movement vector to identify active surfaces of the at least one tooth;
• determining, based on the active surfaces and the movement vector, that surface shape of a crown of the at least one tooth is insufficient for moving the at least one tooth, wherein determining that the surface shape of the crown of the at least one tooth is insufficient includes comparing the active surfaces to a resistance surface of the at least one tooth, wherein comparing the active surfaces with the resistance surface of the at least one tooth comprises comparing a ratio of the active surfaces with desirable orientations to the resistance surface of the at least one tooth to a predefined threshold and wherein determining that the active surfaces is insufficient for moving the tooth comprises determining that the ratio of the active surfaces to the resistance surface of the at least one tooth is below the predefined threshold;
• contouring the at least one tooth, when the surface of the at least one tooth are insufficient for moving the at least one tooth, to adjust the active surfaces of the at least one tooth, wherein contouring includes an addition of material to improve an amount of the active surfaces and designing the shape based on the surface of the at least one tooth with the addition of material that improves the amount of the active surfaces;
• designing a first orthodontic aligner of the series of orthodontic aligners to have a shape based on the contouring of the at least one tooth of the patient so that the first orthodontic aligner, when worn by the patient, moves the at least one tooth from the first position towards the second position along the movement vector;
• and
• fabricating the series of orthodontic aligners including the first orthodontic aligner.