The purpose of this continuing study is to determine the prevalence and progression of gingivitis, epithelial attachment loss, and bone loss in a group of adolescents residing in the U.S. The original cross-sectional study population consisted of approximately 600 Navajos, ages 14-19 years. Twenty-four posterior interproximal sites were examined on each subject. Gingivitis was assessed using a modification of the G.I. Loss of attachment was assessed using Ramfjord's technique. Bone loss was diagnosed from standardized bite-wing radiographs. Analyses indicated a high prevalence of disease: gingivitis (71%); attachment loss (89%); and bone loss (89%). The average number of sites in the mouth affected with the more advanced form of disease (attachment loss and bone loss) was also high: 32% of the sites had attachment loss, and 22% had bone loss. A longitudinal study is in progress with the youngest subjects to investigate microbiologic, systemic and other factors that may contribute to the high prevalence of disease. Two hundred twenty-six 9th and 10th grade students were examined in February 1986, 1987 and 1988 using the same clinical and radiographic techniques. Subgingival plaque samples were obtained from all first molars and analyzed for A, actinomycetemcomitans, B, gingivalis and B, Intermedius. Analyses of first year data indicate that the combination of calculus, gingival bleeding and B,intermedius gave the most parsimonious explanation of the presence of attachment loss. Analyses of the longitudinal data is progressing.
