下颌骨矩形切除术术后并发病理性骨折临床分析

目的：分析与下颌骨矩形切除术术后并发病理性骨折的相关因素，为改进手术方式减少骨折发生提供依据。方法：74例口腔癌病例分别采直角形和曲线形截骨方法进行了下颌骨矩形切除术，术后曲面断层片检查，测量剩余下颌骨高度的最小值并观察有否病理性骨折。结果：5例并发病理性骨折，其中直角形截骨4例，骨折发生率为8．9％；典线形截骨1例，骨折发生率为3．4％。术后并发病理性骨折的病例下颌骨剩余骨段高度最小值为0．96cm(SD,0.03)。骨折均发生于截骨区远中部。结论：保留下牙槽动脉血供．剩余下颌骨高度保留在1cm以上对预防病理性骨折有重要意义；曲线形截骨具有良好的生物力学结构以及较好的术后形态和生理功能，可减少术后骨折发生。

The Postoperative Pathologic Fracture after Marginal Resction of the Mandible

Objectives:To analyze the risky factors of postoperative pathologic fracture of the mandible after marginal resection,with the ultimate goal of improving operation technique and reducing the incidence of the complication.Methods:74 patients with oral cancer underwent marginal resection of mandible for previously untreated oral squamous cell carcinoma .Right-angled osteotomy and curvilinear osteotomy were carried out in this group of patients respectively. Residual bone after mandibulectomy was measured on the panoramic radiogram.The patients were followed up and postoperative pathologic fracture of the mandible was determined.Results:Pathologic fractures of the mandible occurred in 5 patients.4 cases were associated with right-angled osteotomy, and the other one underwent curvilinear osteotomy.The incidences of mandibular fracture of the two groups were 8.9% and 3.4% respectively.The smallest dimension of residual bone is 0.96cm (SD 0.03) in these 5 patients with the complication of pathologic fracture.The sites of fracture were all at the distal angle of the excision.Conclusions:Preservation the blood supply of mandible and maintenance at least a 1-cm thick segment of residual bone are required to reduce the risk of fracture.A curvilinear mandibulectomy not only can keep the mandibular contour and also can decrease the incidence of pathologic fracture.