Background and objective: Obesity has been implicated as a risk factor for several chronic health conditions. Recent studies have reported a relationship between obesity and periodontitis, but few studies have investigated this relationship in adolescents. The purpose of the present study was to investigate the relationship between body composition (i.e. body mass index and body fat) and periodontitis in university students in Japan.

Material and methods: Medical and oral health data were collected in a cross-sectional examination conducted by the Health and Environment Center of Okayama University. Students aged 18-24 years (n = 618), who were interested in receiving an oral health examination, were included in the analysis. The community periodontal index was used to assess periodontal status. Subjects with a community periodontal index score of 0-2 were considered as controls and those with a community periodontal index score of > 2 were considered to have periodontitis. Logistic regression analysis was used to estimate the association between body mass index and periodontitis.

Results: The body mass index of all subjects was < 30 kg/m2. Age and body mass index were significantly associated with the community periodontal index. Logistic regression analysis revealed a 16% increased risk for periodontitis per 1-kg/m2 increase in body mass index (adjusted odds ratio, 1.16; 95% confidence interval, 1.03-1.31; p < 0.05).

Conclusion: Body mass index could be a potential risk factor for periodontitis among healthy young individuals (i.e. those with a body mass index of < 30 kg/m2). It may be useful to include an evaluation of body mass index on a regular basis in university general and oral health examinations.