Diagnostic sub-types, psychological distress and psychosocial dysfunction in southern Chinese people with temporomandibular disorders

The study aimed to assess the distribution of temporomandibular disorders (TMD) sub-types, psychological distress and psychosocial dysfunction in southern Chinese people seeking treatment for TMD using Research Diagnostic Criteria for TMD (RDC/TMD) and investigate potential cross-cultural differences in sub-type prevalence and psychosocial impact. Eighty-seven consecutive patients (77 females; 10 males) with a mean age of 39.3 years (s.d. 12.8) newly referred to the specialist TMD clinic at the Prince Philip Dental Hospital, Hong Kong over a 20-month period took part in the study. RDC/TMD history questionnaire and clinical assessment data were used to derive Axis I and II findings. Group I muscle disorders were the most common and found in 57.5% of patients. Group II (disc displacement) disorders were found in 42.5% and 47.1% of the right and left temporomandibular joints (TMJ) respectively. Group III disorders (arthralgia/arthrosis/arthritis) were revealed in 19.5% and 23.0% of right and left TMJ's respectively. In the Axis II assessment, 42.5% of patients had moderate/severe depression scores, 59.7% had moderate/severe somatization scores and based on graded chronic pain scores 15.0% had psychosocial dysfunction (grade III and IV). While acknowledging the small sample size, the distribution of RDC/TMD Axis I and II diagnoses was fairly similar in Chinese TMD patients compared with Western and other Asian patient groups. However, in Chinese patients, myofascial pain with limited jaw opening and TMJ disc displacement with reduction were more common and a significant number experienced psychological distress and psychosocial dysfunction. The findings have implications for the management of TMD in Chinese people.