From bite to mind: TMD - A personal and literature review

Purpose: The purpose of this study was to present a personal view of the de velopment of prevailing opinions about temporomandibular disorders (TMD) du ring the last half century from a mechanistic to a psychosomatic concept. I t also presents some hypotheses concerning: (1) the role of stress in the e tiology of human oral parafunctions and its relationship to oral stereotypi es in domestic animals; and (2) the pathogenetic mechanisms of masticatory muscle pain. Materials and Methods: The basis for this article was a review of personal experiences derived from clinical and research work with TMD p atients. Studies of both older and more recent literature on TMD and relate d disorders-especially in the fields of stress research, psychosocial medic ine, occupational medicine, and etiology-were also used. Results: A clear l ine is found in the development of the ideas on etiology, pathogenesis, and therapy of TMD, from the mechanistic attitude of Costen syndrome through t he introduction of psychologic and psychophysical theories by the Columbia and Chicago schools to the now increasingly accepted biopsychosocial concep t and the view of refractory TMD as a chronic pain condition. Conclusion: T he formerly dominant bite-centered therapies-including intraoral appliances , the effects of which still are unexplained-appear to be increasingly bani shed to the domain of placebo. Hence, to an ever-increasing extent occlusal treatments are replaced by physiotherapy and cognitive behavior therapy. T he presented hypotheses may have implications for the understanding of the origin of oral parafunction and masticatory muscle pain.