Chow J, Hägg U, Tideman H
Department of Oral and Maxillofacial Surgery, University of Hong Kong.
J Oral Maxillofac Surg. 1995 Dec;53(12):1407-12; discussion 1412-3. doi: 10.1016/0278-2391(95)90665-7.
This study evaluates the postsurgical stability of segmentalized Le Fort I osteotomies with miniplate fixation in patients with maxillary hypoplasia.
Eighteen adult patients who had undergone segmentalized Le Fort I osteotomy for anterior and inferior repositioning of their hypoplastic maxilla were studied radiographically. The positional change of five maxillary landmarks (PNS, ANS, A, U1, and UM) were measured on serial cephalometric radiographs according to a reference frame constructed by using the SN line for superimposition, sella as the origin of the coordinates, and a line parallel to Frankfort horizontal plane as the x-axis. The positional changes of all variables were measured twice, and the means were calculated for analysis. The paired t-test was used for statistical analysis.
Statistically significant mean vertical change (P < .01) was found in the anterior maxilla, with U1 having moved up by 27.8% (1.5 mm) of its initial downward surgical movement by 1 year postoperatively. U1 and UM had moved forward 2.0 mm and 1.5 mm, respectively (P < .01) by 1 year postoperatively, but the bony landmarks had no statistically significant change in their horizontal positions.
Although statistically significant postsurgical changes were found at 1 year postoperatively, overcorrection is not recommended because of the large individual variation observed and the relatively small magnitude of the relapse.
本研究评估采用微型钢板固定的节段性Le Fort I截骨术对上颌骨发育不全患者术后稳定性的影响。
对18例因上颌骨发育不全接受节段性Le Fort I截骨术以进行前下方复位的成年患者进行影像学研究。根据以SN线进行叠加构建的参考框架、以蝶鞍为坐标原点以及以平行于法兰克福水平面的线为x轴，在系列头颅侧位片上测量五个上颌骨标志点（PNS、ANS、A、U1和UM）的位置变化。所有变量的位置变化均测量两次，并计算平均值进行分析。采用配对t检验进行统计学分析。
术后1年，上颌前部出现具有统计学意义的平均垂直变化（P <.01），U1向上移动了其初始向下手术移动量的27.8%（1.5 mm）。术后1年，U1和UM分别向前移动了2.0 mm和1.5 mm（P <.01），但骨标志点的水平位置无统计学意义的变化。
尽管术后1年发现了具有统计学意义的手术变化，但由于观察到个体差异较大且复发幅度相对较小，不建议过度矫正。
