Psychosocial correlates of temporomandibular joint pain and dysfunction. This study examines psychological differences between temporomandibular joint pain and dysfunction (TMJPD) patients, pain controls, and healthy controls. Two hundred and two patients were classified, according to the diagnostic criteria of Eversole and Machado, as either myogenic facial pain (n = 42), internal derangement type I (n = 69), internal derangement type II (n = 85), or internal derangement type III (n = 6). Patients completed the Basic Personality Inventory, the Illness Behavior Questionnaire, the Multidimensional Health Locus of Control, the Perceived Stress Scale, and the Ways of Coping Checklist. Subjects also answered question pertaining to TMJPD symptomatology, including chronicity and severity. After conservative treatment with simple jaw exercise and ultrasound, patients were contacted again at 5 months to complete follow-up questionnaires similar to those previously completed. Comparison groups were comprised of 79 patients attending outpatient physiotherapy clinics for pain-related injuries not involving the temporomandibular joint and 71 pain-free, healthy students. Data were analyzed using multivariate statistics. The results indicate a significant relationship between pain intensity (and to some extent chronicity) and diverse measures of personality among the pain controls but not among the TMJPD patients. This calls into question the validity of assuming individual pain disorders are subsets of a larger, homogenous pain disorder population. TMJPD patients and pain controls score higher on hypochondriasis and anxiety than the pain-free controls but these elevations are not clinically significant. The elevations decrease to normal levels in response to a positive treatment outcome. There were no differences between the TMJPD patients and the pain controls on any of the measures. These results suggests that TMJPD patients do not appear to be significantly different from other pain patients or healthy controls in personality type, response to illness, attitudes towards health care, or ways of coping with stress. 