Analysis of prenatal and passive smoking exposure and Early Childhood Caries among preschool children in Hong Kong. A cross-sectional study

Abstract

Objectives: To assess the prevalence and severity of caries in preschool children exposed to prenatal smoking and passive smoking compared to those not exposed. Methods: A total of 672 children were recruited from 11 kindergartens and underwent examinations for dental plaque and dental caries. Sociodemographic background, oral health-related habits, prenatal smoking, and passive smoking exposure of the children were obtained through validated parental questionnaires. Negative binomial regression using generalised linear equations and binary logistic regressions were employed to assess the impact of smoking exposure and other confounding variables. Results: Children with passive smoking exposure (n = 281) compared to those without (n = 391) were found to have significantly higher dft scores (p = 0.021), but a higher proportion of them also had lower socioeconomic background and poorer oral health habits (p < 0.05). On the other hand, the ECC prevalence and dft scores among children with (n = 246) and without (n = 414) firsthand or secondhand prenatal smoking did not differ. Regression analyses revealed that passive smoking exposure was not significantly associated with ECC prevalence or increased dft scores, but increased child age and risk factors such as lower household income, frequent snacking, and increased plaque scores were associated. Conclusions: Passive smoking exposure was not found to be associated with an increased risk of caries among preschool children. In addition to controlling for common confounders related to passive smoking exposure and dental caries, the study suggests further investigation to quantify the degree and severity of passive smoking exposure in order to establish a more definitive link.