Abstract
INTRODUCTION: Despite warnings of secondhand smoke (SHS) dangers, children are still exposed in unregulated private spaces. This study aimed to assess the association between cumulative multi-source SHS exposure and its effect on children's oral health. METHODS: This cross-sectional study collected smoking patterns and SHS exposure data from parents at King Abdulaziz University Dental Hospital using an Arabic-language questionnaire. Children's oral health was assessed using decayed, missing, and filled teeth (DMFT) scores obtained from dental records. An adjusted negative binomial regression model was used to assess the association between caries score and SHS exposure pattern, either at home, in the car, or at family gatherings, as follows: no exposure, exposure from a single source, two sources, or all three sources. RESULTS: A total of 427 parents answered the questionnaire (children's median age was 10 years, and the median DMFT/dmft index score was 10). Overall, 55.3% of participants reported living in a household with smokers. A gradual positive association was observed between SHS exposure and the DMFT score. Children exposed to SHS from one source had significantly higher mean caries scores than non-exposed children with higher scores observed among those exposed from two sources (p < 0.001). The highest risk was observed in children exposed to SHS at all three sources (p < 0.001). CONCLUSION: A gradual positive association was observed between cumulative multi-source SHS exposure and mean caries scores. Children exposed to SHS from multiple sources had progressively higher mean caries scores than those not exposed.