The prevalence of symptoms related to TMD and their relationship to psychological status

This study aims to determine the prevalence of TMD symptoms in a non-TMD adult population in Israel. The extent to which gender and biological factors related to TMD interact with psychosocial factors in terms of their influence upon the pain experience is assessed. Non-TMD adults were recruited from the general population and completed questionnaires on TMD symptoms as well as a psychological assessment (Research Diagnostic Criteria for Temporomandibular Disorders [RDC/TMD] Axis II, SCL-90, and Perceived Stress Scale). A total of 240 subjects (103 males, 127 females, mean age 35.7±12.5 years) participated. The prevalence of individuals with at least one TMD symptom was 37%, and no gender differences were found. However, significant differences were found between the levels of psychological factors among females and males who did not suffer from chronic pain. In examining the interaction between reported pain and each gender separately (t test, followed by Bonferroni correction), a significant increase was observed in the measures of somatization (pain excluded) (P = 0.01) among men reporting pain, and a tendency to significance regarding the level of depression (P = 0.065). There was no significant increase in any of the measures of psychological distress in the presence of pain among females. The authors' results showed that the gender difference was dependent upon the level of pain, indicating an important role of pain in the development of psychological distress, especially among males. It appears that the psychological state of a person influences the presence of symptoms of functional disorders of the masticatory system. Epidemiological investigations on non-TMD patient populations should use the RDC/TMD to enable comparisons to be made with results of future studies on these patient populations. Keywords: temporomandibular disorders, psychological status, gender, pain, RDC/TMD Axis II