Posição maxilomandibular e dimensões da orofaringe de pacientes classe II antes e após expansão rápida da maxila e uso do aparelho extrabucal

Abstract

The aim of this retrospective study was to evaluate the oropharyngeal dimensions and the maxillary and mandibular position in class II patients, after rapid maxillary expansion (RME) associated with high-pull headgear. The sample consisted of 40 individuals that were divided into two groups. The experimental group consisted of 21 patients, with Class II Division 1 malloclusion who underwent RME associated with a high-pull headgear. The control group consisted in 19 patients with transverse maxillary deficiency, who underwent only RME. The evaluation was conducted using cone beam computed tomography scans in two different times: initial (T1) and 6 months after the proposed treatments for each group (T2). A paired-sample t test was used for intra-group comparisons. To compare the results (T2), it was used an analysis of covariance (ANCOVA) adjusted by baseline measures. No significant changes were found in the oropharyngeal dimensions of the experimental group (p>0,05). The high-pull headgear associated with RME increased the palatal plane inclination and moved down the maxillary A point. On the other hand, the control group showed a significant oropharyngeal area increase (p=0,040) after the RME. The RME moved downward the maxillary A point. There were no significant mandibular changes in both groups.