100例正常人下颌管的三维测量

The 3D location of 100 cases of normal mandibular canals

目的:通过对100例正常人下颌管在第二前磨牙及第一、二磨牙根尖处位置的测量,来确定正常人下颌管在第二前磨牙及第一、二磨牙根尖处正常位置,为临床操作提供理论依据。方法:测量100例17岁以上不同性别分组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(M)到下颌骨下缘最下点(L)的距离;②下颌管中心(M)到与M点在同一水平线的颊侧点(O)的距离;③下颌管中心(M)到与M点在同一水平线的舌侧点(I)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骨壁厚度三者比较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;女性测量结果分布规律与男性相同,其骨壁厚度略较男性相应骨壁为薄。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,对我们在临床操作中如:正颌手术中下颌骨矢状劈开(SSRO)、囊肿刮治术、种植术等有一定的理论依据,为科研、教学提供一种切实可行的方法。

Objective： To identify the normal position of the root tips of lower premolars, first and second molars, the distances through 3-D reconstruction in 100 cases of general population were measured. Methods： The three distances were measured from 100 cases over 17 years old, divided by gender： 1. The distance of Mandible of the Centre （M） under the jaw to the lower edge of the next point （L） ; 2. The distance of Mandible of the Centre （M） and M points to the horizon at the same point of the buccal （O） ; 3. The distance of Mandible of the Centre （M） and M to the point in the same horizontal line at the side of the tongue（I）. Results： The sec- ond premolar root tip of the jaw bone under the margin of the thick wall, the wall thickness of tongue in cheek bone lateral side of the wall in the first and second molars, the lower edge of the mandible hone wall, the tongue side of the wall, cheek bone side walls were thicker through 3-D reconstruction measurement than in normal way. Cheek bone was much thicker than the tongue side of the wall. Conclusion： The way of identifying the normal lower in the second premolar and the first and second molar root tip through the three distances by 3 - D reconstruction will give us lots of help, such as ： Orthognathic operation of the mandible sagittal split SSRO, scaling of cysts, planting of a certain theoretical basis for scientific research and teaching to provide a realistic and practical method.