双侧下颌升支矢状劈开截骨术后稳定性的研究

Stability of hard tissue after bilateral sagittal split ramus osteotomy and setback

目的:主要探讨BSSRO后退下颌骨术后骨的稳定性,了解导致复发的有关因素。方法:46例单纯下颌前突患者,不包括存在偏颌畸形的病例。所有患者于手术前一周(T1)、术后一周(T2)、术后6个月或6个月以上(T3)分别拍摄头颅定位侧位片,测量硬组织的相对位移。结果:BSSRO后退下颌骨后,使得硬组织Li点平均后退了6.5mm,B点平均后退了7.3mm,Pg点是8.5mm,Me点为9.1mm。各标志点的平均复发率为:Li点复发率为23.1%、B点复发率为24.7%、Pg点复发率为25.9%、Me点复发率为26.4%。结论:影响下颌升支矢状劈开截骨后退术后复发的因素很多,其中受髁状突的影响使得下颌骨在向前复发的过程中并不是完全的水平复发,而是水平逆时针旋转复发。复发可能与后退量存在相关关系,但需要超过一定的后退量。

Objective To discuss the stability of hard tissue after bilateral sagittal split ramus osteotomy and setback and comprehend the factors of relapse. Methods BSSRO was performed in 46 cases to setback the mandible. The patients were examined with lateral cephalometric radiographs one week before and one week after and six months or more after surgery. Results After setback the mandible, point Li had setback 6.5mm, point B had setback 7.3mm, point Pg had setback 8.5mm, point Me had setback 9.1mm. The average relapse is: Li 23.1%, B 24.7%, Pg 25.9%, Me 26.4%. Conclusion By the influence of condyle, the relapse of mandible is anti-clockwise rotation and forward, not horizontally forward. Relapse and the distance of setback have correlated relation, but had to over some definited distance.