Mode of Delivery, Prolonged Breastfeeding and Diet as Predictors of Severe Early Childhood Caries: a Multicenter Study in Children Under 3 Years

Purpose This study aimed to evaluate whether the mode of delivery, breastfeeding practices, and dietary habits were associated with severe early childhood caries (S-ECC) in children under 3 years of age from Brazil and the United States. Methods This retrospective study adhered to the STROBE guidelines. Data were retrieved from electronic medical records of 700 children aged 0–3 years who underwent complete oral examinations between August 2021 and November 2023. Collected variables included mode of delivery, diet, type and duration of breastfeeding, nationality, oral hygiene habits, age, and sex. Statistical analyses were conducted using chi-square tests, the Mann–Whitney U test, and multiple linear regression, with a significance level set at 5%. Results The overall prevalence of S-ECC was 59.4% (416/700), with 41.1% of cases from the United States and 18.2% from Brazil. Of the total sample, 51.9% were male and 48.1% female, with a mean age of 1.75 years. In bivariate analyses, vaginal delivery (p < 0.001) and cariogenic diet (p < 0.001) were significantly associated with S-ECC. In the multivariable regression model, older age (B = 0.107, p < 0.001), longer breastfeeding duration (B = 0.005, p < 0.001), and U.S. nationality (B = − 2.918, p < 0.001) remained independent predictors of higher dmft scores. Other variables were not significant. Conclusion S-ECC was highly prevalent in this sample, affecting nearly six in ten children under 3 years of age. While vaginal delivery and cariogenic diet were associated with S-ECC in unadjusted analyses, only age, breastfeeding duration, and nationality emerged as independent predictors after adjustment. These findings underscore the multifactorial nature of S-ECC and the need for early, culturally tailored preventive strategies.