Previous studies have shown that diabetes and obesity increase the severity of periodontal disease—a well-known risk factor for tooth loss. However, the effect of obesity on tooth loss has not yet been fully characterized. Thus, we investigated the association between obesity and residual teeth (number and sites) using a large database of the Japanese population. We used the MinaCare database, composed of data from Japanese health insurance claims and health check-ups in 2015 to select 233,517 subjects from 706,150 based on the availability of BMI, HbA1c, teeth, and smoking information. Obesity was defined as BMI ≥25.0. The number of residual teeth at every age group was correlated with 4 BMI subsets (<18.5, 18.5-24.9, 25.0-30.0, >30.0). The unadjusted and adjusted odds ratios (ORs) for fewer than 24 residual teeth were estimated using logistic regression models. The number of residual teeth decreased with age (p for trend<0.001). Groups with higher BMIs had fewer residual teeth at all ages over 40s (p for trend<0.001). The number of residual teeth in the lowest vs. highest BMI groups in the 50s and 60s were 26.0 ± 3.2 vs. 25.2 ± 3.9 and 24.0 ± 5.0 vs. 23.3± 5.1, respectively. The negative effects of obesity on residual teeth were dominant in the right mandibular first molar. Additionally, smoking enhanced the effect of obesity. The OR for fewer than 24 residual teeth in obese people was 1.47 (95% CI: 1.43-1.52). Although diabetes (defined as HbA1c ≥6.5%) is an independent factor, the OR for fewer than 24 residual teeth in obese people after adjustment with sex, age, smoking status, and diabetes was 1.35 (95% CI: 1.31-1.40). Thus, obesity is an independent risk factor for tooth loss in the Japanese population, suggesting the importance of weight management to maintain oral health in obese people. Further studies are necessary to confirm our findings, due to limitations in our study such as data-availability from only the subject’s dental visit and the exclusion of full dentures and a small number of residual teeth.


M. Hayashi: Employee; Self; Sunstar Group. K. Morino: None. K. Harada: Employee; Self; Sunstar Group. M. Ishikawa: None. I. Miyazawa: None. A. Ishikado: Employee; Self; Sunstar Group. Employee; Spouse/Partner; Sunstar Group. H. Maegawa: Speaker’s Bureau; Self; Astellas Pharma Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Merck Sharp & Dohme Corp., Mitsubishi Tanabe Pharma Corporation, Sanofi K.K., Takeda Pharmaceutical Company Limited.

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