Association between passive tobacco exposure and caries in children and adolescents. A systematic review and meta-analysis

To examine the available evidence on the association between exposure to tobacco use in the womb and in infancy and the presence of caries in primary and permanent dentition in children and adolescents. A systematic review was conducted through searches in 4 data bases (Pubmed, Scopus, Embase and Web of Science), complemented by hand-searching. Of the 559 articles identified, 400 were duplicates. Finally, 28 articles were included in the qualitative review and 21 in the meta-analysis. Their quality was assessed using the Newcastle-Ottawa scale. The quality was medium in 44% of the articles included and high in 56%. The overall meta-analysis gave a significant odds ratio (OR = 1.53, 95% confidence interval 1.39–1.68, Z test p-value = 0.000) and high heterogeneity (Q = 200.3, p = 0.000; I(2) = 86.52%). Separate meta-analyses were also performed for three subgroups: exposure in the womb (prenatal) and caries in primary dentition, which resulted in a significant OR = 1.46 with a 95% CI of 1.41–1.52 (Z test p = 0.000), without heterogeneity (Q = 0.91, p = 0.824; I(2) = 0%); exposure in infancy (postnatal) and caries in primary dentition, with OR = 1.72 (95% CI 1.45–2.05) and high heterogeneity (Q = 76.59, p = 0.00; I(2) = 83.01%); and postnatal exposure and caries in permanent dentition, with OR = 1.30 (95% CI 1.25–1.34) and no heterogeneity (Q = 4.48, p = 0.880; I(2) = 0%). In children and adolescents, a significant though moderate association was found between passive tobacco exposure and caries.