RESUMEN
INTRODUCTION: This study evaluated the expression of nonnutritive sucking habits and the presence of malocclusion in children using day nurseries' facilities. MATERIALS AND METHODS: The 195 children (7-40 months) attending 18 public day nurseries were evaluated clinically in Ponta Grossa, Brazil. Statistical package software was used for descriptive, univariate, bivariate, and multiple logistic regressions of the data about the socioeconomic condition, educational family status, malocclusions, and prevalence of nonnutritive sucking habits among the children. RESULTS: The pacifier users had a statistically significant, explanatory association with open bite [odds ratio (OR) = 10.97; 95% confidence interval (CI): 4.95, 24.31; p < 0.0001]. The children older than 25 months had more open bite than younger children (OR = 6.07; 95% CI: 2.81, 13.11; p < 0.0001). Of the children examined, 35.4% had an anterior open bite, 0.51% had posterior cross-bite, and 1.03% showed finger-sucking habits. A high frequency of pacifier-sucking habits was found (52%), with a significant association between this habit and anterior open bite (p < 0.0001, OR = 7.49; 95% CI: 3.71, 15.15). The 126 children without open bite (36.5%) were pacifier users. There was suggestive, though nonsignificant, evidence of a difference in pacifier use by gender (males, 34%; females, 46%; p = 0.07). The 69 children with open bite (81.16%) were pacifier users and (18.84%) nonusers. The boys showed a slightly greater association with open bite (OR = 21.33; 95% CI: 6.12, 74.40; p < 0.0001) than girls (OR = 5.03; 95% CI: 1.26, 20.00; p = 0.02) in the age group of 25 to 40 months; however, it was not observed in younger children. CONCLUSION: Pacifier use is a predictor for open bite in children from the lower socioeconomic classes using day nurseries' facilities. CLINICAL SIGNIFICANCE: The parents, guardians, and caregivers working in public day nurseries should be advised to monitor nonnutritive sucking habits in order to avoid or minimize the occurrence of malocclusion. It demonstrates that the permanence of the children in day nurseries may be linked with deleterious oral habits, and it discusses strategies to minimize the occurrence of alterations in the normal occlusion.