The present invention provides protective repositioning appliances, accommodating mouth guards, and covering guards that protect an orthodontic patient against impact-induced injuries, as well as related systems and methods. A protective appliance can include teeth receiving cavities shaped to receive and reposition a patient's teeth and can include an occlusal portion having an impact-absorbing compliance. An accommodating mouth guard can include teeth receiving cavities shaped to accommodate a patient's teeth from a first arrangement to a second arrangement and can include an occlusal portion having an impact-absorbing compliance. A covering guard can include a guard segment that covers at least a portion of an appliance. The combination of a guard segment and an appliance can provide an occlusal compliance that absorbs impacts.