Mental-Dental Interface: Window to the Psyche and Soma

MENTAL-DENTAL INTERFACE: WINDOW TO THE PSYCHE AND SOMA DONALD B. GIDDON* Of all our pains, since man was curst, I mean of body, not the mental, To name the worst, among the worst, The dental sure is transcendental.—Thomas Hood Historical Introduction Evolving from the same neural plate cells, the brain and most of the tooth structure and surrounding tissues play common roles in the enhancement of quality of life as well as in human suffering and its relief. Both dental and mental disease also share the distinction of not being a major concern of mainstream medicine. Considering that mental and dental health professionals operate from the same cranial venue and also depend on the mouth for performance of their clinical activities, a more intimate relationship might be expected. For both professions, the structure and function of the orofacial areas provide a window to the rest of the body. Moreover, what is uttered from the mouth is the basis of psychotherapeutic interventions. Their historical antecedents are, however, quite different. The ancestors of modern dentistry were barber surgeons who simply extracted the offending tooth or artisans who fabricated replacement teeth from available material. With better instruments, dentists expanded their surgical activities to the removal of decayed structure and preparation of teeth for filling materials. With increasing emphasis on the broader-based biological basis for medical education, dental education and practice followed, culminating in the first university-based dental school at Harvard in 1867 [2, 3]. Treatment began to include pharmacological and more sophisticated surgiCorrespondence : Harvard University, 188 Longwood Ave., Boston, MA 03115. * Department of Community Health, Brown University.© 1999 by The University of Chicago. All rights reserved. 0031-5982/1999/4301-1 Í21$01.00 84 Donald B. Giddon ¦ Mental-Dental Interface: Window to the Psyche and Soma cal intervention for prevention and treatment ofpain and infection. Similar to medicine, modern dental education and practice has since evolved to the biosocial model for diagnosis and treatment [4-6] . Although psychiatry has been said to begin with the first man who gave advice to another, this specialty had a more ignominious origin than dentistry [7] . Often ascribed to demonic influences, mental illness attracted a variety of questionable practitioners who advocated cures from execution and exorcism, through hypnotism, shock therapy, and psychosurgery, to modern psychotherapy and psychopharmacology [8]. Given the common anatomical locus of psychiatry and dentistry, it was not surprising that extracting teeth was seen as a likely means for relieving mental illness. As recently as the early 20th century, an impacted third molar , for example, was considered a probable cause of mental disease [9, 10]. Following Hunter's theory of focal sepsis and the concept of anachoresis (the local accumulation of pathogens or other particulate material), diseased teeth were, in fact, thought to be responsible for a wide variety of medical conditions, including rheumatic fever, anemia, gastritis, colitis, and kidney disease, in addition to psychopathology [10]. Consequently, institutionalized mental patients often had all their teeth extracted, a practice which also may have served to protect the custodial staff from angry patients [H]. Finally, after hundreds of thousands of presumably sound teeth had been extracted unnecessarily, this unfortunate and unfounded fad ended [12-14]. Interdisciplinary Interaction of Treatment and Preventive Strategies In addition to pathophysiological interaction of the two specialties, treatment and prevention strategies of dental and mental health practitioners can adversely affect the structure and function of the other's domain. For example, substances such as mercury used in dental restorations or fluoride for caries prevention have recentlybeen associatedwith some decline in central nervous system function as well as other pathology [15-17] . Also, wellintended changes in dental occlusion can resultin temporomandibularjoint problems, with consequent orofacial pain and possible depression [18, 19] . Conversely, the armamentarium of the psychiatrist for treatment of mental disorders includes a variety of psychoactive agents. Many of these agents have unpleasant side effects and/or oral pathological implications, particularly on the volume or composition ofsaliva. Xerostomia or hyposalivation , for example, is an unpleasant side effect of more than 400 drugs, many of which are prescribed to treat hypertension and depression [20, 21]. Similar effects have sometimes been observed with the use of psychopharmacological drugs such as...