Systems for protecting and repositioning teeth

A system comprising:

• an aligner having a polymeric shell comprising a plurality of tooth-receiving cavities shaped to reposition teeth of a patient, wherein the polymeric shell is shaped to cover an occlusal surface of the patient's teeth when the aligner is worn by the patient;
• and
• a covering guard for providing protection against impact-induced injuries when coupled with the aligner and when worn by the patient, the covering guard comprising a guard segment shaped to cover at least a portion of the aligner, a combination of the guard segment and the aligner shaped to provide protection against impact-induced injury,
• wherein the combination comprises an occlusal portion disposed between a plurality of upper and lower teeth when the combination is worn by the patient, the occlusal portion having a compliance selected to provide impact absorption during an impact forcing the lower teeth into the upper teeth, and
• wherein the covering guard is configured to be removably coupled to the aligner.