Are there psychologic predictors of treatment outcome in temporomandibular joint pain and dysfunction?

This study explores the relationship between diverse psychologic factors and treatment outcome in temporomandibular joint pain and dysfunction (TMJPD). During assessment, 178 patients with TMJPD were given a pressure pain threshold and tolerance task and 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 questions pertaining to TMJPD symptomatology, including chronicity and severity. After conservative treatment with simple jaw exercises and ultrasound, patients were contacted again at 5 months to complete a follow-up questionnaire package similar to the initial questionnaire battery. Percent reduction in average pain intensity and perceived TMJPD severity were used as outcome criteria. The data were analyzed with discriminant function analyses. One hundred patients responded to the follow-up questionnaire. Patients who reported more than a 50% reduction in average pain intensity tended to be less inclined to accept responsibility for their problems and were slightly better able to distance themselves from their problems than the less improved groups. Those who reported more than a 50% reduction in TMJPD severity indicated that the condition was not associated with an identifiable onset event and that the condition had become moderately worse between onset and first seeking help.