AIM: in the atresia maxillary cases, the most indicated treatment is rapid maxillary expansion that can be achieved by different therapies. In the present research the Hyrax appliance was used in order to evaluate the transverse and vertical outcomes in maxillary base. METHODS: twenty patients of both gender, from 7 to 11 years old, presenting uni or bilateral posterior crossbite were selected. Posteroanterior radiographs were performed before and after expansion. These radiographs were standardized in order to avoid that problems with lack of standardization influence the results. RESULTS AND CONCLUSION: the obtained data showed that the posterior crossbite correction with Hyrax appliance, observed in all the cases, was consequent either to midpalatal suture opening or to molar tipping. JgE-JgD Measurement related to maxillary expansion increased significantly in all the treated cases. According to dental evaluation, vertical measurements did not show significant differences, which is in opposition to the transverse measurements (FTE-FTD; FBE-FBD; LO.BTE; LO.BTD; BTE.BTD). The nasal cavity width also increased significantly (CNE-CND). The standardization method proposed seemed to be reliably useful for maxilla rapid expansion evaluation with posteroanterior radiographs principally for vertical considerations.
Maxillary expansion; Cephalometric; Sutures; Posteroanterior radiograph
