【摘要】 目的观察下颌升支矢状劈开截骨后退术后下颌骨近心骨段的横向变化及长期稳定性。方法对42例行双颌手术+坚固内固定治疗的Ⅲ类错牙合畸形患者术前、术后一周以及术后12个月以上的后前位头颅定位片进行描记、定点测量,并作统计学分析。结果下颌角间距及髁突间距在术中分别增加了4.04mm(P<0.01)和2.11mm(P<0.01);在术后观察期,二者分别减小了1.45mm(P<0.01)和1.80mm(P<0.01);下颌角间距术中增宽量越大,观察期减小的幅度越大。结论经过升支矢状劈开截骨后退下颌骨远心骨段后,下颌骨近心骨段在横向上发生了一定的移位,后前位头颅定位片上表现为下颌角间距及髁突间距的明显增加;在平均20个月的观察期内,二者有不同程度的回复,下颌角间距较术前呈明显的净增宽。更多还原

【Abstract】 Objective To evaluate the transverse displacement of the proximal segment after mandibular setback via sagittal split ramus osteotomy(SSRO).Methods Forty-two patients with skeletal Class Ⅲ malocclusion underwent a bimaxillary surgery including SSRO with rigid internal fixation of the mandible were selected for this study. Posteroanterior cephalograms were taken for each patients at three stages: within one month before surgery (T1); within one week after surgery (T2); a minimum of 12 months of follow-up (T3). All posteroanterior cephalograms were hand-traced on acetate tracing paper, transverse measurements were abtained and analysed.Results After mandibles setback using SSRO technique, the intergonial width and the distance between the most lateral points of the condyles increased by a mean of 4.04mm and 2.11mm (P<0.01) respectively. From T2 to T3, the intergonial width and the distance between the most lateral points of the condyles decreased by a mean of 1.45mm and 1.80mm(P<0.01) respectively. However, the net increase of the intergonial width at T3 stage was still 2.59mm(P<0.01).Conclusion Significant displacement of the proximal segment occurred in transverse dimension after mandibular setback via SSRO, both the intergonial width and the intercondyle width.更多还原