三维颌骨模型在髁突外脱位治疗中的应用

目的：探讨三维颌骨模型及其模型外科在外伤性髁突外脱位复位治疗中的应用。方法：选取9例下颌骨颏部骨折伴髁突外脱位患者，术前行CT扫描并通过快速成型技术制作三维颌骨模型。分析模型髁突外脱位的情况，进行模型外科操作，复位颏部骨折及髁突外脱位并预制个性化重建钛板。术中利用预制的重建钛板配合颌关系的引导，将颏部骨折复位。结果：9例患者在三维颌骨模型外科指导下完成手术，创口均Ⅰ期愈合，颌关系恢复，术后影像学检查见9例患者髁突均完全复位。术后随访6～28个月，患者最大张口度3.1～4.2 cm（中位数3.3 cm），颌关系及颌骨运动功能均正常。结论：三维颌骨模型能全面显示颏部骨折和髁突外脱位情况，利用颌骨的三维模型外科作为平台，可以准确塑形颏部重建钛板，在颏部骨折手术复位的同时将髁突外脱位复位，从而在外伤性髁突外脱位复位治疗中起到良好的辅助作用。

Application of three-dimensional model in treatment of superolateral dislocation of mandibular condyle

Objective: To assess the application of three-dimensional jaw model in treatment of superolateral dislocation of condyle. Methods: Nine patients with superolateral dislocation of condyle and symphyseal fractures were admitted in hospital from June 2008 to June 2013. Spiral CT scan on maxilla and mandible was performed, and three-dimensional jaw model was constructed with rapid prototyping technology. According to conditions of condylar superolateral dislocation model, the operation scheme was designed. The symphyseal fracture line was made and fracture was reduced on three-dimensional jaw model. Individualized prefabricated reconstructive titanium plate was made on symphyseal fracture model. Symphyseal fracture was replaced with individualized prefabricated mandibular reconstruction titanium plate according to occlusal relationship. At the same time, reduction of condylar superolateral dislocation was accomplished. Results: Operations were successfully completed in 9 cases under guidance of three-dimensional jaw model surgery. Operative incision was primarily healed, and occlusal relationship was restored. Postoperative CT scan showed that the locations of condyle in 9 cases were completely restored. Patients were followed up for 6-28 months with a median of 18 months. The maximum of mouth opening was 3.1- 4.2 cm with a medians of 3.3 cm, and the occlusal relationship of all patients was normal after surgery. Conclusion: Three-dimensional jaw model can show complete status of condylar superolateral dislocation and symphyseal fracture. The model can accurately shape symphyseal reconstructive titanium plate and restore condylar superolateral dislocation during reductive surgery.