Egbert M, Hepworth B, Myall R, West R
Department of Oral and Maxillofacial Surgery, University of Washington School of Dentistry, Seattle 98104.
J Oral Maxillofac Surg. 1995 Mar;53(3):243-8; discussion 248-9. doi: 10.1016/0278-2391(95)90217-1.
This study compares two types of fixation: intraosseous wires, skeletal suspension wiring, and maxillomandibular fixation (combined wire fixation; CWF) with rigid internal fixation (RIF) in patients who underwent Le Fort I osteotomy to correct maxillary hypoplasia.
All patients were operated on by the same surgeon using a standard technique, which included bone grafting. The 12 patients in group A were treated with CWF for 4 weeks. Group B was made up of 13 patients who had RIF and training elastics for 4 weeks. Cephalometric analysis using a commercial software package was performed on radiographs that were taken immediately preoperatively (T1), 1 day postoperatively (T2), and at least 1 year postoperatively (T4). The position of the maxilla in relation to the cranial base and Frankfort plane at each time interval was compared.
Postsurgical horizontal change (maxillary position change from T2 to T4) for both groups was in the posterior direction. In group A, six patients had less than 1 mm change, three had 1 to 2 mm change, and three had > 2 mm change. In group B, 10 patients had less than 1 mm change, three had 1 to 2 mm change and 0 had > 2 mm change. Comparison of mean values of groups A and B suggested improved stability with rigid versus wire fixation in the horizontal plane; however, statistical analysis of adjusted mean values showed no significant difference. Vertical changes in maxillary position were also measured from postoperatively to 1 year (T2 to T4). The vertical changes were minimal in those cases of maxillary advancement where no vertical changes were planned; however, there was a statistically significant (P = .0024) improved stability with RIF versus combined wire fixation cases. Comparison of adjusted means showed double the amount of vertical setting 1 year postoperatively in the CWF group.
Overall, 22 of 25 patients with horizontal maxillary advancement had excellent stability at 1 year. Observed trends suggest that RIF may have improved stability over CWF.
本研究比较了两种固定方式：骨内钢丝、骨骼悬吊钢丝和颌间固定（联合钢丝固定；CWF）与坚固内固定（RIF），用于接受Le Fort I型截骨术以矫正上颌骨发育不全的患者。
所有患者均由同一位外科医生采用标准技术进行手术，包括植骨。A组的12例患者采用CWF治疗4周。B组由13例接受RIF并使用训练弹力带4周的患者组成。使用商业软件包对术前即刻（T1）、术后1天（T2）和术后至少1年（T4）拍摄的X线片进行头影测量分析。比较每个时间间隔上颌骨相对于颅底和法兰克福平面的位置。
两组术后水平变化（上颌骨位置从T2到T4的变化）均为向后方向。A组中，6例患者变化小于1mm，3例患者变化为1至2mm，3例患者变化大于2mm。B组中，10例患者变化小于1mm，3例患者变化为1至2mm，0例患者变化大于2mm。A组和B组平均值的比较表明，在水平面内，坚固固定相对于钢丝固定稳定性有所提高；然而，调整后平均值的统计分析显示无显著差异。还测量了从术后到1年（T2到T4）上颌骨位置的垂直变化。在计划无垂直变化的上颌骨前移病例中，垂直变化最小；然而，与联合钢丝固定病例相比，RIF的稳定性有统计学显著提高（P = .0024）。调整后平均值的比较显示，CWF组术后1年垂直调整量是RIF组的两倍。
总体而言，25例上颌骨水平前移患者中有22例在1年时具有出色的稳定性。观察到的趋势表明，RIF可能比CWF具有更好的稳定性。
