CBCT对下颌第三磨牙手术术式选择的影响作用

目的:评估CBCT对下颌第三磨牙拔除术式选择的影响。方法:选择130例符合手术适应症的下颌第三磨牙,通过使用两种放射学检查方法作为术前检查:(1)全景片检查;(2)CBCT检查。在经放射学检查之后,手术方案即被确定下来:拔除术或者截冠术。第一步治疗计划根据全景片拟定,第二步根据CBCT确定。记录经拍摄CBCT后,选择使用截冠术的倾向因素。结果:手术方案是根据第二步治疗计划所执行的。113例(86.9%)样本的第一步治疗计划和第二步治疗计划是一致的,而经拍摄CBCT后的17例(13.1%)样本的治疗计划发生了改变。数据使用SPSS 22分析并应用5%的部分有统计学意义。下颌第三磨牙与下牙槽神经管直接接触时,会极大的影响治疗方案并最终选择使用截冠术。然而,直接接触并非一个充分的影响因素;另外,根的数量、根与神经管之间有无皮质骨、神经管是否位于根的凹陷处以及牙根与神经管接触的长度,也是对于选择截冠术的重要影响因素。结论:CBCT影响了13.1%的治疗计划。CBCT影像中观察到的下颌第三磨牙与神经管管腔的直接接触、神经管在根尖复合体附近弯曲或凹陷的位置、根与神经管之间有无皮质骨以及牙根与神经管接触的长度,对于决定使用截冠术是重要的影响因素。

Effect of CBCT on Selection of Extraction Method for Mandibular Third Molar

Objective:To evaluate the effect of CBCT on the selection of extraction method for mandibular third molar.Methods:130 cases of mandibular third molar were selected,and two radiographic methods were used for preoperative examination.(1)Panoramic radiograph examination;(2)CBCT examination.After radiological examination,the surgical procedure was determined:surgical removal or coronectomy.The first treatment plan was formulated according to the panoramic image,and the second was determined according to CBCT.After the CBCT was taken,the factors for the selection of coronectomy were recorded.Results:The operative plan was performed according to the second-step treatment plan.The first treatment plan of 113(86.9%)samples was consistent with the second treatment plan,while the treatment plan of 17(13.1%)samples after CBCT was changed.When the mandibular third molar was in direct contact with the inferior alveolar neural tube,the final choose was to use the coronectomy.However,direct contact was not an adequate influencing factor.In addition,the number of roots,the presence of cortical bone between the roots and the neural tube,the location of the neural tube in the hollow of the root,and the length of the contact between the root and the neural tube were also important factors influencing the selection of the coronal amputation.Conclusion:CBCT affected 13.1%of treatment plans.The direct contact between mandibular third molars and neural tube cavities,the position of the neural tube bending or depression near the apical complex,the presence of cortical bone between the root and neural tube,and the length of the root and neural tube contact observed in CBCT images were important factors influencing the decision of coronal amputation.