RESUMEN
(1) Introduction. An analysis was made of posterior crossbites in deciduous dentition and their relation to the type of feeding received by the child, with the objective of determining the influence of the way in which the child is fed in the early stages of life on the development of posterior crossbites. (2) Material and methods. A total of 1401 preschool children between 3 and 6 years of age from Seville (Spain) were included in the study. An intraoral exploration was carried out to assess the presence of crossbites (uni- or bilateral, and functional or not). The study was completed with a parent or legal guardian questionnaire exploring the type of feeding received by the child in the first stages of life, as well as the presence of bad oral habits and their duration. (3) Results. A total of 276 children (19.7%) presented posterior crossbite in occlusion. Uponn centering the midlines, 197 were maintained, indicating that 79 were due to premature contacts (functional crossbites). There were no significant differences in crossbites among the children who had received breastfeeding, though bottle-feeding was seen to favor crossbite. (4) Conclusions. No statistically significant relationship was found between posterior crossbites and breastfeeding, though an association between posterior crossbites and bottle-feeding was observed, with the number of crossbites increasing with the duration of bottle-feeding.