Periodontal Disease and Overall Health: A Clinician's Guide

CHAPTER 4History of theOral-Systemic RelationshipNoel M. Claffey, Ioannis N. Polyzois, Ray C. WilliamsINTRODUCTIONIn the last decade, the possible associationbetween oral and systemic health has beenhighlighted in numerous reports. The focus ofattention is mainly periodontitis and its impacton certain conditions. Periodontitis is an infec -tious disease associated with a number of pre -dominantly gram-negative bacteria, and it is nowrecognized that for the initiation and progressionof this disease, a susceptible host is also required.It is also well documented that certain systemicconditions can modify the host’s susceptibility toperiodontitis, but it is only recently that evidencesurfaced about the possi bility of a two-way rela -tionship. Speci fically, perio dontitis has been impli -cated as a potential risk factor for cardio vas culardiseases, respiratory diseases, diabetes mellitus,preterm labor, low birth weight, and renal disease.Interest in the relationship of oral health/periodontal disease to general health is not new,but more of a resurgence in the old and dis creditedcon cept of focal infection. Focal infec tion theorybe came popular in the begin ning of the twentiethcentury because it explained a number of con -ditions for which there was no sci entific explana -tion at the time. It eventually fell in to disreputebecause of a lack of scientific evidence.This chapter examines the history of thehypothesis that micro-organisms would localizefrom the source focus to the distant, systemicfocus and follows, step by step, concepts of theoral-systemic relationship that have evolvedover the years.ANCIENT CIVILIZATIONSAND THE MIDDLE AGESThroughout recorded history, manytheories have been put forward to explainhuman illness. One area of the body that hasbeen repeatedly implicated in the origin ofhuman diseases is the oral cavity. Writings asfar back as from the ancient Egyptians (2100BC) mention tooth pain associated withwomen’s reproductive system diseases. 1 InAssyria, the physician of King Ashurbanipal(669–626 BC) wrote about the troubles ofhis king: “The pains in his head, arms, andfeet are caused by his teeth and must beremoved.” 2 In ancient Greece, Hippocrates(400 BC) recorded two cases in which eradicationof the infections of the mouth appearedto relieve patients of rheumatic-liketroubles of the joints. 3 Aristotle, perhaps thefirst dental anatomist—especially from thestandpoint of comparative anatomy—statedthat “those persons who have the most teethare the longest lived.” 4 In his book, On Hygiene,the Roman physician Galen (166–201AD) emphasized the inter-relationship betweenthe oral cavity and other illnesses. 5From the end of the Roman Empireuntil the middle ages, all sciences fell intoabeyance, and had it not been for the Arabs(who had access to the learning and sciencecontained in Greek manuscripts brought totheir country by Nestorian exiles from By -zantium and Greeks who settled in southernItaly), the bulk of science and knowledgeaccumulated to that date might have beenlost. 4 The next notable advance in dentistryprobably occurred in Italy in the 1400s whena physician named Giovanni d’Arcoli beganfilling decayed teeth with gold leaf; anadmirably progressive step for that time. Heis further credited with stating that for casesof severe dental pain, early intervention was