Third molars and periodontal pathologic findings in middle-age and older Americans.

PURPOSE: To assess the association between the visible presence of third molars and the severity of periodontal pathologic findings on teeth more anterior in the mouth. PATIENTS AND METHODS: The present analysis included dentate participants, 52 to 74 years old, from the Dental Atherosclerosis Risk in Communities study who had undergone an oral examination that included periodontal probing depths (PDs) on all visible teeth, including any third molars. A PD of 4 mm or more and a clinical attachment level of 3 mm or greater were indicator variables for periodontal pathologic features. Explanatory variables were the presence or absence of visible third molars. The covariates included gender, ethnicity, age, income level, education, and smoking status. The outcome variables for periodontal pathologic features were the mean PD, extent (percentage of probing sites) of PDs of 4 mm or more, and the extent (percentage of probing sites) of a clinical attachment level of 3 mm or more. The outcomes between those with and without visible third molars were compared using descriptive statistics and chi-square tests, with significance set at P = .05. Multivariate modeling was performed using Statistical Analysis Systems SAS Proc GLM (SAS Institute, Cary, NC) to calculate the least squared means, adjusting for the study outcome variables and covariates.
RESULTS: The Dental Atherosclerosis Risk in Communities study sample included 6,793 subjects; 80% were white and 19% were black. Most (53%) were 62 to 74 years old and female (54%). Of the 6,793 participants, 2,035 (30%) had at least 1 visible third molar. The presence of a visible third molar was significantly associated with male gender, black race, age younger than the mean of 62.4 years, greater income, and never smoking (all P < .01). A greater mean PD for the first and second molars, the extent of PD of 4 mm or more at the first and second molars, and the extent of a clinical attachment level of 3 mm or more at the first and second molars were all significantly associated with the presence of a visible third molar in the unadjusted and adjusted models.
CONCLUSIONS: In these middle-age and older Americans, the presence of a visible third molar was significantly associated with more severe periodontal disease on teeth more anterior in the mouth compared with those subjects with no visible third molars.