1. Although psychological factors are an important etiological component in producing and perpetuating TMJ disorders a comprehensive view of the problem can be best understood through the concept of multifactorial etiology. 2. Psychological factors operative in TMJ disorders cannot be understood within any single frame of reference. It is appropriate to examine emotional, behavioral, and interpersonal relationships in parallel, not as dichotomous concepts. 3. The symptom complex defined in this review as "TMJ disorders" is the musculoskeletal component of a larger group of microtraumatic signs and symptoms, all of which are manifestations of a generalized injury-producing activity termed dysfunction. 4. More explicit diagnoses need to be identified if definitional problems involving TMJ disorders are to be overcome. 5. Classical psychoanalytic conceptualization of the etiology of TMJ disorders has not been systematically examined, but has been widely accepted and found clinically useful by some therapists. 6. Clinical impressions notwithstanding, there is little evidence to indicate that TMJ disorders are correlated with one specific personality trait. Perhaps more definitive assessments will reveal uniform personality characteristics in subclasses of TMJ patients. 7. Emotional factors (e.g., anxiety, fear, frustration, and anger) play a significant role in the etiology of TMJ disorders, in that they elicit muscular tension and oral habits. Although it would appear unlikely that emotionally induced muscle activity is a "necessary" factor, it is probable that it will be found a "sufficient" cause for TMJ disorders. 8. Learning principles, should not be considered as an alternative etiological position but should be viewed as a framework upon which any psychological theory of etiology must be based. 9. The presence of chronic pain in TMJ patients may be of as much clinical significance in the prognosis as the physical findings associated with the disorder itself. 10. The potential placebo effect resulting from any treatment, coupled with other nonspecific effects of the doctor's attitudes, remains a powerful tool that can be utilized in treating TMJ disorders. A vital ingredient in the placebo effect is the quality of the doctor-patient relationship. 11. Patient evaluation should not only include a) a search for the immediate organic stimulus or biomechanical disturbance, but also b) an assessment of situational or chronic anxiety and other emotional factors and c) an observation of interpersonal styles of behavior commonly associated with the chronically sick patient. 12. Unilateral etiological views of TMJ disorders and rigid treatment approaches need modification. Treatment involving simultaneous dental and psychological approaches appears to have more promise.