Alterações tridimensionais imediatas da via aérea superior após cirurgia ortgnática com rotação anti-horária em pacientes retrognatas

Abstract

The purpose of this study was to quantify, through cone beam computed tomography (CBCT), the immediate three-dimensional changes in the oropharynx following bimaxillary orthognathic surgery (OS) with counterclockwise (CCW) rotation, in different surgical advancements. CBCT were taken at two distinct time intervals, preoperative (T0) and immediately postoperative, up to 15 days after surgery (T1). A total of 88 tomographic scans of 44 class II patients (11 men and 33 women) were selected and divided into three groups according to the following mandibular advancement in millimeters (mm): G1 (< 5 mm), G2 (between 5 and 10 mm) and G3 (> 10 mm). Dolphin Imaging® software was used to measure the medial sagittal area (MSA), volume, and minimum cross-sectional axial area (CSA) in each group. Statistical analysis was performed using a paired Student’s t-test for the samples. No significant difference was observed in patients from G1, while G2 presented statistical improvements in CSA only (p< 0.05). Remarkable changes in all measures were observed when the advancements were superior to 10 mm (G3), with the CSA showing the most prominent change. The present study demonstrated that an at least 10 mm B point advancement in CCW was needed to improve the entire oropharynx.