CBCT在减少下牙槽神经损伤风险中的应用

Application of Cone Beam Computed Tomography in Reducing the Risk of Interior Alveolar Nerve Injury

目的探讨CBCT在减少行下颌阻生第三磨牙拔除术治疗的患者下牙槽神经损伤风险中的应用价值。方法选取2014年3月~2015年4月于本院治疗的下颌神经管与第三磨牙根端重叠的患者,经评估下牙槽神经易损伤病例共64例,其中下颌阻生第三磨牙81侧,对患者行CBCT检查。选取具有多年临床经验的口腔外科医师、影像医师各两名,分两组根据CBCT图像以及曲面体层片对拔除第三磨牙患者的下牙槽神经损伤风险进行预估,同时设计相应的手术方案,对两组医师的设计方案进行测评。结果与曲面体层片比较,CBCT图像可呈现下颌神经管与阻生磨牙间三维图像的空间分布,可让医师做出更为精准的手术方案（P〈0.001）。结论在对行下颌阻生第三磨牙拔出术患者的下牙槽神经损伤的风险评估中,CBCT图像较曲面体层片更具识别力,可有效帮助医师设计更为合适的手术方案。

Objective To discuss the application value of cone beam computed tomography（CBCT） in reducing the risk of inferior alveolar nerve injury in patients who have underwent mandibular third molar extraction surgery. Methods The research selected patients with mandibular canal overlapped by third molar root canal from March 2014 to April 2015. The assessment showed that there were sixty-four cases of inferior alveolar nerve injury, among which there were eighty-one sides of impacted mandibular third molars. All the sixty-four patients underwent CBCT examination. Two experienced denta surgeon and two radiologists were chosen to conduct preliminary assessment of the risk of interior alveolar nerve injury in patients undergoing third molar extraction surgery based on CBCT and panoramic tomography images. Meanwhile the correspondent surgical plans were designed, the design schemes proposed by the two groups of physicians were tested and evaluated. Results Compared with images of panoramic radiography, the CBCT image analysis could show the three dimensional images of the spatial distrubution between mandibular canal and impacted molars and thus allowed physicians to make surgical planning more accurate（P0.001）. Conclusion During the risk assessment of interior alveolar nerve injury in patients underwent mandibular third molar extraction surgery, the images of CBCT was more discriminating compared with images obtained from panoramic radiography, which could effectively help physicians choose more appropriate surgical plans.