Prevalence of temporomandibular disorder subtypes, psychologic distress, and psychosocial dysfunction in Asian patients.

AIMS: To use the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) to investigate the physical diagnoses, psychologic distress, and psychosocial dysfunction in Asian TMD patients. The RDC/TMD Axis I and II findings were compared to those of Swedish and American TMD patients. METHODS: One hundred ninety-one patients (53 male and 138 female) referred to 2 institutionalized TMD clinics in Singapore were enrolled in the study. The mean age of the predominantly Chinese population (83.2%) was 33.6 +/- 9.3 years. Data from a RDC/TMD history questionnaire and clinical examination were fed directly by patients and clinicians into a computerized diagnostic system (NUS TMDv1.1). Axis I and II findings were generated on-line, based on RDC/TMD rule engines. Data were automatically exported to SPSS for statistical analysis. RESULTS: Group I (muscle) disorders were found in 31.4% of the patients; Group II (disc displacement) disorders were found in 15.1% and 15.7% of the patients in the left and right temporomandibular joints, respectively; and Group III (arthralgia, arthritis, and arthrosis) disorders were found in 12.6% and 13.0% of the patients in the left and right joints, respectively. Axis II assessment of psychologic status showed that 39.8% of patients experienced moderate to severe depression and 47.6% had moderate to severe nonspecific physical symptom scores. Psychosocial dysfunction was observed in only 4.2% of patients based on graded chronic pain scores. CONCLUSION: Axis I and II findings of Asian TMD patients were generally similar to their Swedish and American cohorts. In all 3 populations, women of child-bearing age represented the majority of patients. Muscle disorders were the most prevalent type of TMD. A substantial portion of TMD patients were depressed and experienced moderate to severe somatization.