Efeitos dento-esqueléticos da expansão rápida de maxila assistida cirurgicamente com e sem disjunção pterigomaxilar : um ensaio clínico randomizado duplo-cego

Abstract

Transversal discrepancy of dental arches is a common problem founded among patients who need orthodontic treatment. The treatment of choice for transverse maxillary deficiency in adult patients is the surgically assisted rapid maxillary expansion (SARME). There is not a consensus yet on which is the best surgical protocol and what dento-skeletal changes occur after SARME. In this context, the aim of this thesis is to evaluate and compare, using cone beam computed tomography, skeletal and dental changes produced by two SARME techniques, with (+PD) and without (−PD) pterygomaxillary disjunction. This study was designed as a randomized, double-blind clinical trial. Patients were divided between two groups according to SARME technique. Computerized tomography scans were performed before surgery, after one month and at the end of the stabilization period. Twenty-four eligible patients were equally distributed in both groups. Maxillary, palatal and alveolar bone expansion, as well as tooth expansion and tipping at the molars and canines areas, were evaluated in 03 follow-up periods. Both techniques demonstrated a significant transversal dentoalveolar expansion at the molars and canines areas, with no statistical difference between the groups. The SARME +PD group showed greater posterior palatal bone expansion and lesser molar tipping. The SARME −PD group provided more dental expansion in the molar area. In the anterior region, the SARME −PD group showed greater palatine and alveolar expansion. In conclusion, SARME with or without PD are reliable techniques for maxillary expansion, although these techniques present slight differences at the patterns of skeletal and dental changes. The PD seems to facilitate a greater degree of posterior bone expansion, while its absence favors greater dental expansion. There is a positive correlation between the PD and the opening of the palatal expander device with a greater posterior alveolar and palatal expansion, while the non-disjunction correlates with greater anterior dental, alveolar and palatine expansion.