Longitudinal study of signs of temporomandibular disorders (TMD) in orthodontically treated and nontreated groups.

This study measured the prevalence and incidence of signs of temporomandibular (TM) disorders in both a group undergoing orthodontic treatment in the University of Florida graduate orthodontic program and a control group. A questionnaire pertaining to the patients' reports of signs and symptoms of TM disorder and a clinical examination were administered by a trained dental examiner. Data collection sessions occurred at baseline (before treatment) and at 12-month intervals to 24 months. Data were also collected for the control group at the same time intervals. There were 102 patients (43 boys, 59 girls) mean age 15.3 years. An untreated control group of 41 nonorthodontically treated subjects mean age 16.2 years was used. The incidence of TM signs for the treatment group and control group were not significantly different. Preliminary results are in agreement with the contention that orthodontically treated patients are not more likely to develop TM signs while undergoing treatment. Results underscore the changing, inconstant, and ephemeral nature of TM signs in many persons over the course of time.