基于CBCT对下颌管位置的测量分析

The location of normal mandibular canal based on CBCT measurement

目的:应用CBCT对正常人群下颌管在第二前磨牙及第一、二磨牙根尖处位置的测量,来确定其正常位置关系。方法:测量120例18岁以上正常人群第二前磨牙及第一、二磨牙根尖处位置的3个距离:①下颌管中心(A)到下颌骨下缘最下点(B)的距离;②下颌管中心(A)到与A点在同一水平线的颊侧点(C)的距离;③下颌管中心(A)到与A点在同一水平线的舌侧点(D)的距离。每个距离测量3组,取其平均值。结果:男性第二前磨牙根尖处的下颌骨下缘骨壁最厚,其舌侧骨壁厚于颊侧骨壁。在第一磨牙及第二磨牙处,下颌骨下缘骨壁、舌侧骨壁、颊侧骨壁均增厚,且颊侧骨壁厚于舌侧骨壁;女性测量结果及规律与男性相同,其骨壁厚度略较男性骨壁为薄。结论:利用这3个空间距离来确定正常人下颌管在第二前磨牙及第一、二磨牙根尖处的位置,对正颌手术中下颌骨矢状劈开术,囊肿刮治术,种植术等提供理论依据。

Objective： To identify and measured distances between the mandibular canal and root apex of the mandibular premolars,the first and the second mandibular molar respectively by CBCT of general population. Method： The three distances were measured on 120 cases over 18 years old,included the distance from the centre（ A） of the mandibular canal to the lower edge of mandible（ B）,the distance from the centre（ A） of the mandibular canal to the buccal side of mandible（ C）,the distance from the centre（ A） of the mandibular canal to the lingual side of mandible（ D）. Each distance was measured three times,and taken the average. Results： The distance from the root apex of mandibular second premolar to the lower edge of mandible was thickest and the wall of buccal side was thicker than the lingual side in males. In the area of the first and the second mandibular molar,the wall of buccal and the lingual side,and to the lower edge of mandible were get more thicker. Meanwhile,the wall of buccal side was thicker than the lingual side. The mean value of the females were smaller than the males. Conclusion： Based on the mean value of distances to identify the position of the mandibular canal to the root apex of the mandibular premolars,the first and the second mandibular molar,it can provide theoretical basis for the clinical surgery,such as orthognathic operation of the mandible sagittal split,scaling of cysts.