Relationship between dental caries and changes in body mass and body fat in children during 5 year follow-up

Previous studies have suggested that dental caries in children are associated with obesity, but the direction of the association is unclear. The aim of this analysis was to investigate associations between caries and weight gain over 5 years among 534 children aged 6-10 y at baseline, using secondary data analysis of the New England Children's Amalgam Trial. Multivariable repeated measures models were used to test associations between caries and body mass index (BMI) or body fat percentage (BF%), adjusting for confounders. At baseline, the mean (SD) number of carious surfaces was 9.3 (6.5). Approximately one-third of the children were overweight or obese, with a mean (SD) BF% of 22.9% (10.6). Baseline number of carious surfaces on primary or permanent teeth was not predictive of changes in BF% or BMI-for-age over follow-up. However, greater cumulative treatment levels over time in primary teeth were associated with greater increases in BF% (boys, 10 surface-years Beta=0.12; girls, Beta=0.13, p<0.001); among girls, permanent teeth filled surfaces were also associated with BF% changes (Beta=0.25, p<0.001). Interestingly, children with higher baseline BMI-for-age or BF% had a lower incidence of new caries at the end of 5-year follow-up (BMI z-score, caries Beta= -0.10, p=0.01; BF%, caries Beta= -0.01, p=0.01), adjusting for baseline caries and other factors. These results suggest bi-directional associations between children's oral health and weight gain. Given the epidemic of childhood obesity and high prevalence of caries in children, semi-annual dental visits may be an opportunity for early intervention and prevention of both public health problems.