LAUSR

OBJECTIVES To determine the association between chronotype-type and the prevalence of caries among in-school pupils aged 6-16-year-olds residing in a sub-urban area in Nigeria. METHODS This secondary analysis of a dataset collected in 2019 from 1502 children aged 6-16-year-old attending private and public primary and secondary schools in Ife Central Local Government Area, Nigeria. The dependent variable was caries prevalence. The explanatory variable was participants' chronotype profile (morning, intermediate and evening). The confounding variables were caries risk factors (socioeconomic status, age at last birthday, sex, use of fluoridated toothpaste, frequency of consumption of refined carbohydrates and oral hygiene status). Poisson regression analysis was conducted. RESULTS Data of 1001 (66.6%) students were retrieved. Of these, 59 (5.9%) had caries, 42 (4.2%) were evening type, 526 (52.5%) were intermediate type, and 433 (43.3%) were morning type. There was no significant association between chronotype and the prevalence of caries though children who were intermediate type (APR= 0.83; 95%CI: 0.41-1.66) and morning type (APR= 0.57; 95% CI: 0.27-1.18) were less likely to have caries than were those who were evening type. CONCLUSION The children and adolescents' chronotype was not a significant risk indicator for caries in the study population.