Method: One hundred and four Thai children in Mahidol University Dental Clinic with the age six year and under (mean age=47.62 + / - 12.29 months) were sampled . Caries and plaque examination of children and their mothers were conducted. All parents were completed the questionnaires regarding demographic data of children and parents, feeding and dietary habit, oral hygiene care, and childs dental visit.
Results: Twenty-nine percent of children were caries-free and the mean dmft of children was 7.00 + / - 6.15. Twenty six percent of children had dmft ranging from 6 to 10. Six statistically significantly protective factors for dental caries were found in the analysis. These were: fluoride supplementation, having water fed after bottle feeding, cleaning oral cavities for babies under one year of age, mothers level of education beyond high school and having milk as a snack. Children having sweets and desserts regularly, having the bottle held in the mouth while sleeping, and plaque accumulation, were three factors that found to be positively associated with dental caries. When using multivariate model for prediction of dental caries among studied children, having the bottle held in the mouth while sleeping was the most significant predictor in the studied model.
Conclusions: The results suggest that children who have the bottle held in the mouth while sleeping is the highest risk group in the studied children.