Purpose: Assess the association between visible third molars (VTM) and periodontal pathology in Third National Health and Nutrition Examination Survey (NHANES III).
Materials and methods: Data were obtained on 5,831 persons aged 18 to 34 from the NHANES III. Relevant to the present study was the presence of VTM and the assessment of periodontal disease in 2 randomly selected (1 maxillary and 1 mandibular) quadrants. Periodontal measures included gingival index, pocket depth, and attachment level on mesiobuccal and buccal sites on up to 7 teeth (excluding third molars) per quadrant. Second molars were compared for periodontal pathology based on the presence or absence of a VTM in the same quadrant. Associations were determined using odds ratios and 95% confidence intervals. Weighted multivariable models were fit using logistic regression, and variances were adjusted to account for the complex sampling design using SUDAAN (Research Triangle Institute, Research Triangle Park, NC).
Results: A VTM was associated with twice the odds of a probing depth 5+ mm (PD5+) on the adjacent second molar, while controlling for other factors associated with VTM and periodontal disease. Other factors positively associated with PD5+ in the model were age 25 to 34 years, smoking, and African American race.
Conclusions: The finding of more severe periodontal conditions associated with VTM in these young adults indicates that third molars may have a negative impact on periodontal health. The relationship between third molars and periodontal disease pathogenesis deserves further study using longitudinal data.