Association of symptoms and signs of TM disorders in an adult population

Most population-based studies of TM disorders report a discrepancy between the frequency of symptoms and the frequency of signs of functional disturbances of the temporomandibular joint. In addition, studies have reported varying relationships between subjectively perceived symptoms and signs found on clinical examination. This study examines this relationship in 148 Canadian adults who were part of a larger sample of 677 subjects who completed a telephone administered symptom questionnaire. Symptoms were reported by 63.5% and signs were found in 88.1%. While a degree of discordance was observed, there was a close and statistically significant association between symptoms and signs. This was the case whether summary variables or individual symptoms and signs were used as the dependent variable and whether proportions with or absolute numbers of symptoms and signs were examined. The validity of the symptom questionnaire was examined in order to assess its ability to identify "cases" of TMD. Validity tests showed a sensitivity of 81.4% and a specificity of 48.3%. When "false" positives and "true" positives were compared, the former were found to be significantly less likely to report pain.