Body mass index and dental caries in New Zealand pre-school children: A population-based study

Pre-school dental caries is a significant public health problem and may be associated with the growth and nutritional status of children. This study aimed to investigate the association between body mass index (BMI) and early childhood caries (ECC) among pre-school children.

This population-based retrospective study involves all 5-year-old children who resided in northern New Zealand and received school entry dental examinations between 1 January 2014 and 31 December 2015. ECC status was determined with the decayed missing filled teeth (dmft) score obtained from a routinely collected regional dental data set. Objectively measured BMI information was obtained from the 'Before School Check' (B4SC) Programme. Logistic regression analyses were used to assess the association between BMI and the occurrence of ECC (dmft score ≥ 1). Ethnic subgroup analyses were also conducted.

Of the 27 333 children involved in this analysis, 11 173 (40.9%) had ECC with a mean dmft score of 1.85, and 3948 (14.4%) were overweight and 2964 (10.8%) were obese at school entry. The prevalence of ECC was higher in overweight and obese children but in subgroup analyses by ethnicity, this positive association was observed in European children only (adjusted odds ratio for overweight children compared to normal weight children: 1.16; 95% CI: 1.02, 1.32 and adjusted odds ratio for obese children: 1.20; 95% CI: 1.00, 1.45).

ECC is highly prevalent in New Zealand children and associated with higher BMI in children of European ethnicity.