Three-dimensional evaluation of changes in the upper airway,natural head position and hyoid bone position in skeletal Class Ⅲ patients after bimaxillary surgery
Objective To assess short-and long-term changes in the upper airway,natural head position and hyoid bone position in skeletal Class Ⅲ patients after bimaxillary surgery.Methods In this retrospective study,the cone-beam computed tomography(CBCT)of skeletal Class Ⅲ patients was taken before surgery(T0),3 months after surgery(T1)and 2 years after surgery(T2).Three-dimensional images were created to assess postoperative changes and the correlation between the upper airway,natural head posi-tion and hyoid bone was analyzed.Results Thirty skeletal Class Ⅲ patients(13 men and 17 women)who underwent bimaxillary sur-gery with a mean(SD)age of 21 years(a range of 17-30 years)were evaluated.A significant decrease was observed in the volume of palatopharynx,glossopharynx and total airway after T1 and T2.There was a significant correlation between changes in the position of the mandible and changes in the volume of the upper airway(P＜0.05).The NSL/OPT angle and the NSL/CVT angle were greater after Tl and T2.The change in the NSL/CVT angle was positively correlated with the change in palatopharyngeal and glossopharyngeal volume(P＜0.05).Conclusion Bimaxillary surgery may cause a decrease in upper airway volume,an increase in the cranio-cervical angle,and a downward and backward movement of the hyoid bone.Changes in the cranio-cervical angle may cause changes in the upper air-way.
upper airwayskeletal Class Ⅲbimaxillary surgerycone-beam computed tomography
万方数据
维普
