AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 78:79-92 (1989) z Caries Prevalences Among Geochemical Regions of Missouri C.F. HILDEBOLT, M. ELVIN-LEWIS, S. MOLNAR, J.K. McKEE, M.D. PERKINS, zyxwvu AND K.L. YOUNG zyxwvu Department of Radiology, Mallinckrodt Institute of Radiology, St. Louis, Missouri 63110 (C.FH.1; Department ofsiomedicine, School ofDental Medicine (C.RH., M.E.-LJ, Department ofAnthropology (S. zyxw M.), and Medical Computing Services GroupIDepartment of Anthropology (J.K.M.), Washington University, St. Louis, Missouri 63130; Bureau ofDental Health, State of Missouri, Jefferson City, Missouri 65102 (M.D.P., K.L. Y) KEY WORDS: Fluoride, Water fluoridation Epidemiology, Geochemical factors, Trace elements, ABSTRACT Our objectives were to determine how the prevalences of caries in elementary school children vary between geochemically defined regions of the state of Missouri and to compare this variation with that found for prehis- toric Missouri inhabitants (Hildebolt et al.: Am. J. Phys. Anthropol. 75:l-14, 1988). Caries data on 6,584 school children were used in the study of second and sixth graders drinking optimally and suboptimally fluoridated water. Geochemical regions were based on maps recently published by the United States Geological Survey. Differences in mean caries scores and proportions of children with caries were tested by analysis of covariance, analysis of variance, Student t, and chi-squared tests. We found that caries prevalences do vary between the geochemical regions of the state. In the total sample, however, there were no significant differences between those children drinking opti- mally fluoridated water and those drinking suboptimally fluoridated water. We conclude that there is variation in caries rates among geochemically de- fined regions of the state and that geochemical factors associated with young parent materials may be antagonizing the action of fluoride. The caries-beneficial property of fluorine is the divisions. Such divisions have been made well established, but other geochemical fac- for the state of Missouri as the result of data tors in the environment are also likely to collected during a recent geologic survey. have an influence on caries rates (Curzon This geochemical survey of Missouri is the and Cutress, 1983). Much of the data that most comprehensive study of its kind ever suggest the influence of these other factors conducted in the nation (Cannon, 1978). Dur- come from recent epidemiological surveys ing the study, 7,000 samples were analyzed that point to several trace elements and to for 30 to zyxw 40 geochemical factors, including the buffering capacity of water as likely car- concentrations of trace elements, hydrogen ies-beneficial agents (Barmes et al., 1970; ions, nitrates, sulfates, and carbonates. So Bowen et al., 1977; Glass et al., 1973; Scham- far, over 150 geochemical maps have been schula et al., 1978). Because of the multifac- published as a result of this survey and are toral etiology of caries and the potential for available through the United States Geolog- numerous interactions between fluorides and ical Survey (USGS). These maps were used geochemical factors, it is reasonable to con- to validate the geochemically defined regions sider not a single but multiple geochemical that were used in our study (Hildebolt et al., factors in caries surveys (Featherstone, 1983; 1988). With these regions and recent caries Helle and Haavikko, 1977; Hopps and 0’- Dell, 1981). As an initial step in such a sur- vey, distinct geographic divisions can be defined on the basis of geochemical combi- nations Of soils snd waters contained within Received November 9, 1987; accepted August 10, 1988. (c) 1989 ALAN R. LISS, INC.