Is Obesity Associated With Dental Caries in Primary Dentition? Findings From a Birth Cohort in Southern Brazil

Nutritional disorders and dental caries share common risk factors, including diet and socioeconomic position, but the association between these two conditions remains unclear. The aim of this study was to investigate the potential association between overweight/obesity and the occurrence of dental caries in primary dentition.

This longitudinal study, conducted using data from the 2015 Pelotas Birth Cohort, utilised information collected at birth, 24 months and 4 years of age. The exposure variable was the obesity collected by BMI (body mass index), at 24 months, using anthropometric measures (weight and height) and classified according to WHO guidelines. Covariates included sex, child's and maternal age, socioeconomic factors (family income and maternal education) and sugar consumption data. The outcome was dental caries at the age of four, assessed using several variables: early childhood caries (ECC), encompassing all activity including white spots and restorations; severe early childhood caries (S-ECC), which refers exclusively to cavitated lesions; and the dmft (Decayed, Missing and Filled Teeth) index. Descriptive analysis was carried out and regression models were tested.

From the 4275 eligible participants, 3374 children (50.5% boys and 49.5% girls) composed the analytical sample. At 24 months, 2474 (73.3%) children were healthy weight (95% CI 71.8; 74.8) and 900 (26.7%) presented overweight/obesity (18.8% overweight and 7.9% obese). Concerning dental caries at the age of four, 37.6% had ECC (including white spots and restorations) and 21.4% had S-ECC. Among children classified as healthy weight at 24 months, 38.6% presented ECC at 4 years of age. Among obese children, the prevalence of ECC was 34.8%. A similar pattern was observed for S-ECC: the prevalence was 22.0% among healthy weight children, 19.9% among overweight and 19.1% among obese children. The Poisson regression analysis adjusting for confounding factors showed no difference between groups.

In conclusion, this cohort study in Brazilian children at the age of four did not observe meaningful associations between overweight/obesity and dental caries in primary dentition. The findings suggest that obesity in childhood should not be considered a risk factor for caries development in children.