Abstract: Objective: To measure and analysis the changes of the hyoid bone and the pharyngeal airway space after the bilateral sagittal split ramus osteotomy (BSSRO) treatment in Class III patients. Method: 50 Class III patients treated with BSSRO were comprised in this review. Patients underwent CBCT examination one week before, two weeks and six months after BSSRO operation. The saggittal and transversal measurements, cross sectional areas were computed, together with the changes of the position of hyoid bone. Using paired t test to analysis the measured values. Results: The pharyngeal airway space was significantly reduced after orthognathic treament. The hyoid bone significantly moved by 2.64 mm backwardly and 1.56mm downwardly in 2 weeks after treatment; and revived to 0.97 mm backwardly and 0.99 mm downwardly in 6 months after treatment. Additionally, we had found  the trend to return to normal position  both with airway space and hyoid bone. Conclusion: The clinicians should pay more attention that mandibular setback surgery(BSSRO) might not only caused the hyoid bone downward and backward and decreased the pharyngeal airway space, but also could possibly predispose the development of obstructive sleep apnea hypopnea syndrome (OSAHS).

Key words: bilateral sagittal split ramus osteotomy, mandibular protrusion, pharyngeal airway space, cone beam CT

摘要： 目的： CBCT测量分析下颌后退手术治疗下颌前突畸形，对舌骨位置和气道间隙变化的影响。方法：选取单纯下颌前突畸形患者50例为研究对象，均接受经口内下颌骨升支矢状劈开截骨术，于正颌手术前1周、术后2周、术后6个月拍摄锥形束CT，测量治疗前后咽腔最窄处的矢状径、冠状径、截面积，同时舌骨点的三维位置，分析咽腔间隙大小及及舌骨体位置变化。测量数值配对t检验。结果：所有患者术后咽腔间隙均呈现缩窄趋势。舌骨发生了后下移位，其中术后2周向后、向下平均移动距离分别为2.64、1.56 mm，术后6月向后、向下移位分别为0.97、0.99 mm。术后2周咽腔的矢状径、冠状径及咽腔间隙分别为11.71 mm、3.05 mm、320.67 mm2，术后6月时分别为14.64 mm、3.23 mm、414.85 mm2。即随时间推移，舌骨位置及咽腔间隙有恢复正常范围的趋势。结论：双侧下颌骨升支矢状劈开截骨后退术后，舌骨向后下移位，咽腔气道缩小，有可能导致睡眠呼吸暂停综合征的发生，临床需予以重视。

关键词:  双侧下颌矢状劈开截骨术, 下颌前突, 咽腔, 锥形束CT

CLC Number: 

• R782.2