There have been few previous prospective studies of periodontal disease and CHD, and the data are inconsistent. A study of 9,760 adult participants in the National Health and Nutrition Epidemiologic Follow-up Study indicated a small, but statistically significant, 25% increased risk of CHD in persons with periodontal disease at baseline, compared to those with minimal periodontal disease, after a median follow-up of 14 years (6). A similar size increase in risk of CHD was also reported for persons with complete tooth loss at baseline in that study. However, information on cigarette smoking, a potentially important confounder of these associations, was available only for a subsample of the study population. A second prospective study, based on combined data for 1,147 participants in the Normative Aging Study and the Dental Longitudinal Study, also indicated an association of periodontal disease and CHD. Analyses conducted after an average of 18 years of follow-up showed that individuals with high alveolar bone loss at baseline (defined as >20% whole mouth bone loss) had a statistically significant 50% increased risk of developing heart disease after controlling for age, body mass index, systolic blood pressure, cholesterol level and diabetes (7). There was also an approximate twofold increase in risk of fatal CHD (controlling for age, smoking, systolic blood pressure, diabetes) and a threefold increase in risk of stroke (controlling for age, smoking, diastolic blood pressure, diabetes, family history of heart disease, education) associated with high alveolar bone loss at baseline. However, the lack of detailed information on cigarette smoking (current smokers were defined as men who smoked one or more cigarettes daily) raises the possibility that residual confounding by smoking (and perhaps other risk factors) may have contributed to the findings of this study. Finally, no association was observed between self-reported periodontal disease and subsequent CHD in a six-year follow-up study of 44,119 male health professionals (8). Among men who reported pre-existing periodontal disease, however, men with ≤10 teeth at the beginning of follow-up, compared with men with ≥25 teeth, had an almost 70% increased risk of CHD.