摘要:Background: Early childhood caries (ECC) is one of the most prevalent chronic diseases among children. The aim of this cross-sectional study was to investigate the association between nocturnal breastfeeding, snacking habits, or other risk factors and ECC in 18- to 23-month-old Japanese children. Methods: Study subjects were 1675 children aged 18 to 23 months. A self-administered questionnaire was completed by parents or guardians of the children. The survey contents included such things as number of decayed, missing, and filled teeth per child, smokers in the home, nocturnal breastfeeding habit, snack times, kinds of snacks consumed ≥4 days a week, kinds of drinks consumed ≥4 days a week, parents brushing their child’s teeth daily, and the use of fluoride toothpaste. Logistic regression analysis was performed to estimate the odds of ECC. Results: The average number of decayed, missing and filled teeth was 0.10. The prevalence of dental caries was 3.3%. Nocturnal breastfeeding habits were reported in 357 subjects (21.3%). After excluding items of multicollinearity, significant associations were observed between ECC and nocturnal breastfeeding, drinking or eating sweets after dinner every day, and the intake of candy, soda and/or isotonic drinks ≥4 days a week. Conclusions: This study suggests that nocturnal breastfeeding and snacking habits are correlated with ECC.