Li M Z, Wang X X, Li Z L, Yi B, Liang C, He W
Department of Oral and Maxilloficial Surgery, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China.
Department of Stomatology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2019 Feb 18;51(1):182-186. doi: 10.19723/j.issn.1671-167X.2019.01.031.
To explore the application accuracy of virtual preoperative plan after the condylectomy via intraoral approach under computer assisted surgical navigation, and to analyze the location and cause of the surgical deviation to provide reference for the surgical procedure improvement in the future.
In the study, 23 cases with condylar hypertrophy (11 with condylar osteochondroma and 12 with condylar benign hypertrophy) in Department of Oral and Maxilloficial Surgery, Peking University School and Hospital of Atomatology from December 2012 to December 2016 were treated by condylectomy via intraoral approach under computer assisted surgical navigation. The patient's spiral CT data were imported into ProPlan software before operation, and the affected mandibular ramus was reconstructed three-dimensionally. The condylar osteotomy line was designed according to the lesion range, and the preoperative design model was generated and introduced into the BrainLab navigation system. Under the guidance of computer navigation, the intraoral approach was used to complete the condylar resection according to the preoperative design of the osteotomy line. Cranial spiral CT of the craniofacial region was taken within one week after operation. three-dimensional reconstruction of the mandibular ramus at the condylectomy side was performed, and the condylar section was divided into six segments (anterolateral, anterior, anteromedial, posteromedial, posterior, and posterolateral) and the corresponding regional measurement points P1 to P6 were defined. Then the preoperative virtual model and the postoperative actual model were matched by Geomagic studio 12.0 to compare the differences and to analyze the accuracy of the operation.
All the patients had successfully accomplished the operation and obtained satisfactory results. Postoperative CT showed that the condyle lesion was completely resected, and the condylar osteotomy line was basically consistent with the surgical design. No tumor recurrence or temporomandibular joint ankylosis during the follow-up period. The postoperative accuracy analysis of the condylar resection showed that the confidence intervals measured by the six groups of P1 to P6 were (-2.26 mm, -1.89 mm), (-2.30 mm, -1.45 mm), (-3.37 mm, -2.91 mm), (-2.83 mm, -1.75 mm), (-1.13 mm, 0.99 mm), and(-1.17 mm, 0.17 mm), where P3 group was different from the other 5 groups. There was no significant difference between the P5 and P6 groups and the difference between the other four groups was statistically significant.
Under the guidance of computer navigation, the intraoral approach can be performed more accurately. The surgical deviation of each part of the osteotomy surface is mainly due to excessive resection. The anterior medial area of the anterior medial condyle represents the most excessive resection. The posterior and posterior lateral measurement points represent the posterior condylar area. The average deviation is not large, but the fluctuation of the deviation value is larger than that of the other four groups. The accuracy of computer-assisted subtotal resection has yet to be improved.
探讨计算机辅助手术导航下口内入路髁突切除术后虚拟术前计划的应用准确性，分析手术偏差的位置及原因，为今后手术操作的改进提供参考。
本研究选取2012年12月至2016年12月在北京大学口腔医学院口腔颌面外科就诊的23例髁突肥大患者（11例髁突骨软骨瘤，12例髁突良性肥大），采用计算机辅助手术导航下口内入路髁突切除术进行治疗。术前将患者的螺旋CT数据导入ProPlan软件，对患侧下颌升支进行三维重建。根据病变范围设计髁突截骨线，生成术前设计模型并导入BrainLab导航系统。在计算机导航引导下，采用口内入路按照术前设计的截骨线完成髁突切除。术后1周内行颅面部螺旋CT扫描，对髁突切除侧下颌升支进行三维重建，将髁突断面分为6个节段（前外侧、前、前内侧、后内侧、后、后外侧），并定义相应区域的测量点P1至P6。然后通过Geomagic studio 12.0将术前虚拟模型与术后实际模型进行匹配，比较差异并分析手术准确性。
所有患者均成功完成手术，效果满意。术后CT显示髁突病变完全切除，髁突截骨线与手术设计基本一致。随访期间无肿瘤复发及颞下颌关节强直。髁突切除术后准确性分析显示，P1至P6六组测量的置信区间分别为（-2.26 mm，-1.89 mm）、（-2.30 mm，-1.45 mm）、（-3.37 mm，-2.91 mm）、（-2.83 mm，-1.75 mm）、（-1.13 mm，0.99 mm）和（-1.17 mm，0.17 mm）,其中P3组与其他5组不同。P5和P6组之间无显著差异，其他四组之间的差异具有统计学意义。
在计算机导航引导下，口内入路手术可更准确地进行。截骨面各部位的手术偏差主要是由于切除过多。髁突前内侧区域的前内侧部分切除最为过度。后及后外侧测量点代表髁突后区。平均偏差不大，但偏差值的波动大于其他四组。计算机辅助次全切除的准确性还有待提高。
