Aligners with elastics and associated systems

An aligner comprising:

• a three-dimensionally (3D) printed shell comprising:
• an interior surface comprising a plurality of tooth-receiving cavities shaped to reposition a patient's dentition from a first arrangement toward a second arrangement, and
• an exterior surface disposed opposite the interior surface;
• and
• one or more elastic regions directly fabricated on the 3D printed shell,
• wherein, when the aligner is worn on the patient's dentition, the aligner applies one or more forces onto the patient's dentition via the one or more elastic regions to affect repositioning of the patient's dentition from the first arrangement toward the second arrangement.

A system comprising:

• a first aligner comprising:
• a three-dimensionally (3D) printed shell comprising:
• an interior surface comprising a plurality of first tooth-receiving cavities shaped to reposition a patient's dentition from a first arrangement toward a second arrangement, and
• an exterior surface disposed opposite the interior surface, and
• one or more elastic regions directly fabricated on the 3D printed shell,
• wherein, when the aligner is worn on the patient's dentition, the first aligner applies one or more forces onto the patient's dentition via the one or more elastic regions to affect repositioning of the patient's dentition from the first arrangement toward the second arrangement;
• and
• a second aligner comprising a plurality of second tooth-receiving cavities shaped to reposition the patient's dentition from the second arrangement toward a third arrangement.