Caesarean delivery and early childhood caries: Estimation with marginal structural models in Brazilian pre-schoolers.

OBJECTIVE: This study analysed the association between caesarean section and early childhood caries (ECC), estimating the effects using regression and causal inference models. METHODS: This was a historical cohort study of 697 mother-child dyads, conducted in São Luís, Brazil. The caesarean section was the exposure, and the severity of ECC (dmft) was the outcome. Covariates household income, maternal schooling, maternal hypertension, maternal obesity and birth weight were adjusted for in the models. The effects were estimated by Poisson regression (Means Ratio-MR) and causal inference using a marginal structural model (MSM) (MR and Average Treatment Effect-ATE coefficients), weighted by the inverse probability (IPW) of exposure. RESULTS: Caesarean section was protective against caries in the bivariate (MR 0.81; CI 0.70-0.94; P = 0.005) and multivariate (MR 0.78; CI 0.67-0.91; P = 0.002) models. In MSM analyses, the caesarean section had no effect on ECC (ATE = -0.35; P = 0.107), controlling for IPW of exposure. CONCLUSION: The apparent association between caesarean section and ECC severity seems spurious, as it did not persist after employing a superior approach to estimating causality.

Assessment of mothers' participation in a program of prevention and control of caries and periodontal diseases for infants.

OBJECTIVE: To evaluate mothers who participated in an educational and preventive program for infants in relation to their knowledge on oral health practices. METHODS: A cohort study was performed with 112 mothers and their babies aged 0 to 8 months and registered in the project "Promotion of Oral Health in Early Childhood" from the Federal University of Maranhão (Northeast Brazil). Initially, semi-structured interviews on the level of mothers' knowledge as to their babies' oral health were conducted. The oral cavities of the infants were also examined regarding: level of plaque, gingival bleeding, and dental caries. Then, educational lectures were ministered and, after a year of follow-up, new interviews and clinical examination were performed. For statistical analysis, the chi-square and Fisher exact tests were applied, being significant p<0.05. RESULTS: Before the educational lectures, 93% of the mothers performed oral hygiene of their babies and 57.3% performed it at daytime and nighttime. After the lectures, all mothers performed the oral hygiene (p>0.02) and 74.7% performed it at daytime and nighttime (p=0.01). There were no differences regarding the consumption of cariogenic food in the initial and final questionnaires (p>0.05). Initially, 5.6% of dental surfaces had caries; 29.7%, plaques; and 11.9%, gingival bleeding. After the lectures, only 0.4% of the dental surfaces had caries (p<0.0001); 2.4%, plaque (p<0.0001); and 10.61%, gingival bleeding (p<0.0001). CONCLUSIONS: Knowledge acquisition is essential to improve oral health conditions.