Correction of posterior crossbite in the primary dentition.

This study shows the types of malocclusions that can be treated in the primary dentition and advocates correction of maxillary constrictions from five years of age onwards, when such constrictions lead to crossbites. A preferred method to treat maxillary constrictions is through rapid maxillary expansion (RME) with the Haas expander, even in the early stages of occlusal development. This paper presents a cross-sectional evaluation and a long-term follow-up of the upper permanent incisors during the active and passive phases of RME and shows no signs of root or pulp alterations.