摘要目的:探讨上颌骨截骨和定位导板在正颌外科上颌骨Le Fort Ⅰ型截骨术中的应用，观察其消除髁突移位带来的术后误差的效果。方法:选择2018年1月至2020年11月，蚌埠医学院第一附属医院口腔颌面外科收治的需行上颌骨Le Fort Ⅰ型截骨术的骨性错 患者。术前患者均采用64排螺旋CT行全头颅扫描，将获得的DICOM格式数据导入Simplant软件，重建颌骨的虚拟三维模型，在虚拟三维头颅上定点测量分析，并虚拟手术模拟上颌骨Le Fort Ⅰ型截骨，3D打印上颌骨截骨及定位导板，手术中采用上颌骨截骨导板确定截骨线及上颌骨前徙位置。将患者术前虚拟设计方案测量数据与术后复查的虚拟头颅测量数据导入SPSS 22.0软件，行 t检验分析2组数据的差异性。 结果:研究共纳入8例需行上颌骨Le Fort Ⅰ型截骨术的骨性错 患者，男5例，女3例，年龄18～39岁，平均24.8岁。8例手术均顺利，术中导板和牙支持式 板定位准确，应用顺利，术后伤口均一期愈合，咬合稳定，关节无弹响。术前设计方案与术后三维重建的10个测量指标比较，差异无统计学意义( P>0.05)。 结论:上颌骨截骨和定位导板，可精准地控制上颌骨的三维移动，提高正颌外科中上颌骨Le Fort Ⅰ型截骨术的精度，手术效果与术前设计方案高度一致。

abstractsObjective:The aim of this study was to explore the application of maxillary osteotomy plate and positioning guide plate in maxillary Le Fort Ⅰ osteotomy to eliminate the postoperative error caused by condylar displacement.Methods:Patients suffered from skeletal malocclusion and needed Le Fort Ⅰ osteotomy between January 2018 and November 2020 were selected from the Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital of Bengbu Medical College. All patients were scanned with 64 slice spiral CT. The DICOM format data were analyzed using the Simplant software to reconstruct the virtual three-dimensional model of the jaw before operation. Then, the measurement of indexes and the maxillary Le Fort Ⅰ osteotomy were carried out on the virtual three-dimensional model, respectively. 3D-printed osteotomy guide plate and positioning guide plate were used to determine the osteotomy line and the position of maxillary advancement. 3D-printed tooth supported occlusal plate was used to support the mandibular sagittal split and retraction. The differences of 10 indexes between the two groups (virtual operation and surgery) were analyzed by paired t test using SPSS 22.0. Results:A total of 8 patients (5 males and 3 females) needed maxillary Le Fort Ⅰ osteotomy aged from 18 to 39 years old were recorded. The deviation of age in these patients was 24.8. The 3D-printed guide plate and tooth supporting occlusal plate were positioned accurately in surgery. All the operations were successful with primary healing of the incision and stable occlusion, and without joint clicking. There was no significant difference on the 10 indexes between the groups of virtual operation and surgery ( P>0.05). Conclusions:The application of maxillary osteotomy plate and positioning guide plate can effectively and accurately control the three-dimensional movement of the maxilla and improve the precision of maxillary Le fort Ⅰ osteotomy in orthognathic surgery, making the surgical effect highly consistent with the preoperative design.