Relation between sucking habits and dental characteristics in preschoolchildren with unilateral cross-bite

The relationship between sucking habits and dental characteristics of unilateral cross-bite in 4-yr-old children (n = 76) was studied. The cross-bites were classified on the variables "number of teeth involved", incisor "overjet" and "overbite", "terminal plane shift", "midline shift", "asymmetric maxillary dental arch" and "max./mand. arch width difference". Type of sucking habit (dummy, finger) and its duration and intensity were analyzed from a questionnaire answered by the parents. The "max./mand. arch width difference" in the canine region was found to be negatively related to the intensity and duration of the sucking habit, and also negatively related to sucking a dummy compared to finger sucking. The study indicates that the "duration" and "intensity" of the sucking habit have a negative influence by reducing the transverse width of the maxillary arch in children with a unilateral cross-bite. Dummy sucking was more detrimental to the transverse dimension in the canine region than finger sucking.