Prediction of demand for treatment of temporomandibular disorders

Baseline (BL) data on signs and symptoms characteristic of temporomandibular disorders (TMDs) were analysed in 67 young non-patients participating as controls in a clinical trial. Data on the incidence of demand for treatment of TMD were collected during the 4-year follow-up period, and, by means of a mailed questionnaire, during an additional 2 years. The variables analysed included palpation and auscultation of the joints, palpation of the muscles of mastication, experience of joint sounds, of pain on jaw movements, of ear symptoms, awareness of a clenching habit, and frequency of headache. A present-absent dichotomy was applied throughout. Palpation tenderness of masticatory muscles was significantly (P=0.02) more often present at BL in those who subsequently requested treatment than in those who did not. The same was true of the combination of palpatory tenderness and clenching habit (P=0.007), whereas the clenching habit alone failed to show a significant difference (P=0.06). However, the predictive values remained too low to be clinically useful, with a possible exception of the negative predictive value of muscle tenderness. The findings indicate that the variables conventionally used to describe the functional status of the masticatory system are at best of modest value in the estimation of individual risk of TMD in healthy young subjects.