Longitudinal Association between Obesity and Dental Caries in Adolescents.

OBJECTIVE: To investigate the longitudinal association between obesity and dental caries among adolescents. STUDY DESIGN: The present cohort study was conducted among a random sample of 12-year-old adolescents in Hong Kong. Two rounds of follow-up were performed when the participants were aged 15 and 18 years. A total of 668 participants were included at age 12 years, and 282 of them completed all 3 phases of data collection. Body mass index, waist circumference, waist-to-hip (WHR) ratio, waist-to-height ratio, and triceps skinfold thickness were measured as indices of obesity. Dental caries were assessed by the number of decayed, missing, and filled permanent teeth (DMFT). RESULTS: The percentage of underweight adolescents increased significantly from 6.0% to 23.8% during the observation period (P <.001). Body mass index, waist circumference, waist-to-hip ratio, and waist-to-height ratio were related to frequency of tooth brushing at age 15 and 18 years. The prevalence of dental caries was 25.5%, 53.2%, and 62.1% at 12, 15 and 18 years, respectively. At age 18 years, mean DMFT of participants whose WHR at age 15 years was below the median value was 0.707 times (ie, 29.3%) lower than the DMFT of those whose WHR was above the median (P = .028). Participants with greater DMFT at age 15 demonstrated significantly increased probability of having WHR above the median (OR 1.135; 95% CI 1.01-1.28; P = .041) at age 18 years. CONCLUSION: There is longitudinal association between central obesity and dental caries experience among adolescents aged 15-18 years.