数字化技术辅助修复下颌骨截骨术后第二下颌角

目的探讨利用数字化技术辅助修复下颌骨截骨术后形成的第二下颌角的临床效果。方法1996年1月至2017年12月,南部战区总医院整形外科共收治下颌骨截骨术后产生第二下颌角伴下颌边缘不流畅或双侧不对称患者39例,男8例,女31例,年龄18~40岁。通过CT行全头颅扫描,应用Mimics 13.0软件建立颅骨三维模型,采用计算机辅助设计下颌骨截骨线,根据设计线进行二次截骨,并于术后6个月时再次行下颌骨三维重建。在重建图像上测量修复前、设计后及术后6个月时下颌角角度,应用配对样本t检验比较两侧对称性及设计结果与最终结果的相符程度,P<0.05为差异具有统计学意义。结果39例患者均顺利完成手术,1例术后15 d出现血肿,经口腔换药清洁、引流、加压包扎,术后2周B超下观察血肿已吸收,所有患者均无感染、神经损伤及颏突意外骨折。术后随访6个月,39例患者的下颌角角度由术前左侧118.12°±18.08°、右侧114.60°±16.01°改善至左侧121.28°±6.96°、右侧121.32°±5.88°,术前左右两侧比较差异有统计学意义(t=1.744,P=0.045),术后6个月左右两侧比较,差异无统计学意义(t=-0.074,P=0.529)。比较各例设计后下颌角角度与术后6个月患者的实际情况,差异无统计学意义(t=0.527,P=0.601),且患者均对第二下颌角及面型改善效果满意。结论应用数字化技术辅助修复下颌骨截骨术后形成的第二下颌角,既可避免术中损伤下齿槽神经血管束及颏神经,亦可有效改善患者面型。

Digital technique-assisted repair of the secondary mandibular angle deformity after mandibular osteotomy

Objective To repair the secondary mandibular angle caused by madibular osteotomy by using digital technology and to make quantitative comparative evaluation.Methods Thirty-nine patients with secondary mandibular angle with unsmooth mandibular margin or bilateral asymmetry after mandibular osteotomy in Southern Theater General Hospital from 1996 to 2017 were included.The three-dimensional model of skull was established by CT skull scan and Mimics 13.0 software.The computer aided design was used to carry out the secondary surgical repair according to the design line,and the mandibular angle was quantitatively measured and evaluated before and after the revision operation.The mandibular angles before,after design and after restoration were measured on the reconstructed images,and the bilateral symmetry and the consistency between the design result and the final result were compared by Paired-t sample test.P<0.05 indicates statistical difference.Results All the 39 patients completed the operation successfully,and 1 case developed hematoma 15 days after operation,which was drained and bandaged by oral dressing.Two weeks after operation,the hematoma was resolved.No infection,nerve injury and accidental fracture of mental process were found in all patients.During the 6-month follow-up,the mandibular angle of 39 patients improved from 118.12°±18.08°on the left side and 114.60°±16.01°on the right side to 121.28°±6.96°on the left side and 121.32°±5.88°on the right side.There was significant difference between the left and right sides before operation(t=1.744,P=0.045),but there was no significant difference between the two sides about 6 months after operation(t=-0.074,P=0.529).The angle of mandibular angle after design was compared with the actual outcomes of patients 6 months after operation and there was no significant difference(t=-0.527,P=0.601).All the patients were satisfied with the improvement of the secondary mandibular angle and facial shape.Conclusions The application of digital technique to repair the secondary mandibular angle after mandibular osteotomy not only avoids the injury of inferior alveolar neurovascular bundle and mental nerve,but also effectively improves the facial shape of the patients.