锥束CT在下颌角肥大整形术中的应用

Application of cone beam computer tomography in mandibular angle reduction

目的 探讨锥束CT在下颌角肥大整形术中的作用.方法 随机选取20例青年女性行锥束CT扫描,获得DICOM格式的三维重建数据,将数据导入Invivo 5 软件,显示下颌神经管走行,并测量下颌神经管距下颌升支后缘及下颌骨体下缘的距离.选择临床11例下颌角肥大的患者,术前进行锥束CT扫描,定位下颌神经管,并进行弧形截骨线设计,指导临床操作.结果 下颌神经管与下颌后缘及下缘的距离呈先减小后增大的趋势：下颌升支前缘水平至第一磨牙水平所对应的距离逐渐减小,至第一磨牙后缘水平所对应的距离最小,左侧为（8.93±1.78）mm,右侧为（8.16±1.51）mm,之后距离逐渐增加.下颌神经管距下颌角最短距离,左侧为（19.25±3.79）mm,右侧为（19.15±3.17）mm.临床应用CBCT可术前准确定位下颌神经管,并辅助截骨设计,手术效果良好.结论 锥束CT可为下颌角肥大整形提供准确的下颌神经管解剖影像,提高了手术的准确性和安全性.

Objective To evaluate the application of the cone beam computer tomography （CBCT） in the mandibular angle reduction. Methods Twenty young women were randomly selected and scanned by CBCT to obtain the DICOM format data, and then they were transformed into Invivo 5 software to display mandible neural canal and measure the distances between the neural canal and the posterior border or inferior border of the mandible. Eleven patients preparing for mandibular angle reduction received CBCT scan and the position of the neural canals were determined. Based on the anatomical data the ostectomy lines were designed to guide the operation. Results The distances between the mandible neural canals and the mandibular borders gradually decreased at first, and then increased. The nearest point responsed to the posterior margin of first molar, which were （8.93 ± 1.78） mm on the left and （8.16± 1.51 ） mm on the right. The nearest distance between the angle and the neural canal were （19.25± 3.79） mm on the left and （19.15 ± 3.17 ）mm on the right. In clinical practice, CBCT images helped accurately localize mandible neural canal and made the design of ostectomy. The results of the operations were good. Conclusion The CBCT system could provide precise anatomy image for mandible neural canal, thus make the mandibular angle reduction much more accurate and safe.