摘要 目的 评估恒牙早期的骨性Ⅱ类错[XCyh.tif;%90%80]畸形下颌后缩患者经Twin-block矫治器治疗后，舌骨位置及上气道矢状径的变化，为临床预防阻塞性睡眠呼吸暂停综合征（OSAHS）提供理论支持。 方法 选取恒牙早期的骨性Ⅱ类错[XCyh.tif;%90%80]畸形下颌后缩患者20例为试验组，采用Twin-block矫治器矫治；选取恒牙早期的骨性Ⅱ类错[XCyh.tif;%90%80]畸形下颌后缩患者20例为对照组，采用固定矫治器矫治。试验组矫治时间为（18.4±2.6）个月，对照组矫治时间为（18.6±2.0）个月，其中试验组包括佩戴Twin-block矫治器及建立稳定咬合关系两个阶段，两组分别于佩戴矫治器前2周及矫治完成后拍摄头颅侧位X线片。利用WinCeph 8.0软件对收集的数据进行测量，采用SPSS 17.0软件对矫治前后的数据进行配对t检验。 结果 矫治完成后，对照组舌骨位置及上气道矢状径无显著变化（P<0.05）；试验组AH-SN、AH-FH、AH-MP、AH-OP、AH-PP、AH-Ge、AH-Me、AH-C3、AH-NPo、C3-Me距离显著增加，AH-O距离显著减少（t=－5.178～－2.382，P<0.05）；PNS-Ba、PNS-UPW、SPP-SPPW、Mc1-Mc2、U-MPW、TB-TPPW、V-LPW距离均显著增加（t=－6.728～－3.716，P<0.05）。 结论 Twin-block矫治器可使恒牙早期骨性Ⅱ类错[XCyh.tif;%90%80]畸形下颌后缩患者的上气道矢状径明显增大，舌骨前下移位。 Abstract：Objective To investigate the changes in hyoid bone position and sagittal diameter of the upper airway after Twin-block correction in patients with mandibular retraction due to class Ⅱ skeletal malocclusion deformity in early permanent dentition, and to provide theoretical support for clinical prevention of obstructive sleep apnea/hypopnea syndrome (OSAHS). Methods A total of 40 patients with mandibular retraction due to class Ⅱ skeletal malocclusion deformity in early permanent dentition were enrolled, among whom 20 treated with Twin-block appliance were enrolled as experimental group and 20 treated with a fixed appliance were enrolled as control group. The correction time was (18.4±2.6) months in the experimental group and (18.6±2.0) months in the control group. The patients in the experimental group underwent two stages of wearing the Twin-block appliance and establishing a stable occlusion relationship. Lateral cephalometric radiograph was obtained at 2 weeks before the wearing of the appliance and after correction. WinCeph 8.0 was used for measurement, and SPSS 17.0 was used to perform the paired t-test of related data before and after correction. Results After correction, the control group had no significant changes in hyoid bone position and sagittal diameter of the upper airway (P<0.05), while the experimental group had significant increases in the distances of AH-SN, AH-FH, AH-MP, AH-OP, AH-PP, AH-Ge, AH-Me, AH-C3, AH-NPo, and C3-Me and a significant reduction in AH-O distance (t=-5.178--2.382,P<0.05), as well as significant increases in the distances of PNS-Ba, PNS-UPW, SPP-SPPW, Mc1-Mc2, U-MPW, TB-TPPW, and V-LPW (t=-6.728--3.716,P<0.05). Conclusion In patients with mandibular retraction due to class Ⅱ skeletal malocclusion deformity in early permanent dentition, Twin-block appliance can significantly increase the sagittal diameter of the upper airway and
