Biobehavioral predictor variables of treatment outcome in patients with temporomandibular disorders

A biopsychosocial intervention approach has been found to be effective in the treatment of chronic medical conditions such as temporomandibular disorder (TMD). Recent research has begun to evaluate factors that may predict positive treatment response to such an approach. The present study was designed to assess the ability of two variables (a muscle disorder diagnosis and an elevation of Scale 3 on the MMPI-2) to predict treatment outcomes in a sample of chronic TMD patients. A total of 121 patients with chronic TMD were randomly assigned to one of five different treatment conditions: biofeedback, cognitive-behavioral skills training (CBST), combined CBST/biofeedback, no treatment/random control, or no treatment/not interested in treatment control. All patients were administered the standard Research Diagnostic Criteria (RDC) for TMD at pretreatment. They were reevaluated at posttreatment and 1 year after intervention. There were also four patient classification groups: dual presence of MMPI-2 Scale 3 elevation and an RDC muscle disorder diagnosis; MMPI-2 Scale 3 elevation and no RDC muscle disorder diagnosis; no MMPI-2 Scale 3 elevation and an RDC muscle disorder diagnosis; and no MMPI-2 Scale 3 elevation and no RDC muscle disorder diagnosis. Results revealed that the patient classification group variable significantly affected posttreatment pain levels. Such findings have important treatment implications and also suggest the significant biopsychosocial underpinnings of a chronic medical condition such as TMD.