下颌管及其分支与下颌第三磨牙关系的影像学观察

目的:利用椎形束CT(CBCT)及全景片观察下颌管及其分支在下颌第三磨牙区域的情况。方法 :对179名患者的216颗第三磨牙进行CBCT及全景片检查。在全景片及CBCT上观察下颌管及其分支在第三磨牙区域走向及与第三磨牙的关系。结果:全景片上观察到有4例下颌管有分支,CBCT观察到有22例有分支;下颌管分支与第三磨牙的关系:A类有8例,B类有6例,C类有2例,D类有6例,其中,分支位于第三磨牙颊侧的有7例,舌侧的有6例,位于第三磨牙牙根下方的有9例。结论:利用CBCT可以对下颌管及下颌第三磨牙的空间位置进行更好地观察。CBCT对下颌管分支有更高的检出率。

Imaging Modalities for Assessment of the Position of MTM and Mandibular Canal

Objective: To observe the applied anatomy of mandibular canal(MC) and braches in mandibular third molar(MTM) region by CBCT and panoramic radiography.Methods: 179 patients with 216 MTMs undertaken panoramic radiography and CBCT were retrospectively reviewed.Yamada classification was used to record the anatomic relationship of MC and MTM.Result: 4 cases with branch of mandibular canal were detected in panoramic radiographs and 18 cases with branch were detected by CBCT.There were 8 cases in type A,6 cases in type B,2 cases in type C,and 6 cases in type D.Meanwhile,there were 7cases that branches located at the buccal side of third molar,6 cases at the lingual side, and 9 cases below the root of third molar.Conclusion: When we want to bring the important anatomical structures into view,CBCT 3-D images are useful and better than panoramic radiography.