Unexpected temporomandibular joint findings during fixed appliance therapy.

Six hundred consecutively debonded patients were retrospectively examined for the development of any temporomandibular joint signs or symptoms that developed during orthopedic/orthodontic treatment. Sixteen (2.6%) patients were found to have developed unexpected temporomandibular joint findings during treatment. Considering such a small sample, no conclusive results could be found, but several tendencies seemed to be apparent. Those types of patients who seemed to be most predisposed to developing temporomandibular joint problems included female Class II patients with excessive overjet and overbite and moderate to severe crowding of the lower arch. Ninety-three percent of the patients experienced posterior net condylar change in spite of using several different treatment mechanics. The types of treatments used included FJO appliances, headgear, Class II and Class III elastics, no elastics of any kind, extraction and nonextraction. This small study seems to suggest that temporomandibular joint signs and symptoms are changing, inconsistent, and ephemeral in many orthodontic patients regardless of the treatment mechanics.