正常青年人下颌管全长三维走向及下颌骨形态的锥形束CT测量

目的采用锥形束CT（CBCT）分析正常青年人下颌管在下颌骨内的三维位置以及下颌骨的形态特征，为临床下颌骨手术提供解剖学依据。方法 对29例个别正常进行CBCT扫描，用InVivo 5软件对下颌骨进行三维重建，定位标记点，测量下颌骨形态以及下颌管在其内的三维走行。采用SPSS 17.0软件对测量值进行统计分析。结果 下颌管舌侧骨皮质厚度明显较颊侧骨皮质薄。下颌管到颊侧骨皮质的距离从近中到远中逐渐增加，到舌侧骨皮质、牙槽嵴顶的距离从近中到远中逐渐减小，到下颌下缘的距离在第一磨牙处最小，第二前磨牙处最大。下颌体截面高度、宽度、皮质骨厚度左右侧无统计学差异，从中线至远中，下颌体截面高度、舌侧下1/3皮质骨厚度逐渐减小，上截面宽度、唇/颊侧上1/3皮质骨厚度逐渐增大。部分测量项目性别间有统计学差异。结论下颌管入下颌孔后渐渐远离舌侧而向颊侧靠近，然后又逐渐远离偏向舌侧，但其总体走行还是靠近舌侧。男性下颌骨较女性更坚厚。CBCT能精确地显示下颌神经管的走行及其与周边结构的关系。

Three-dimensional survey of the whole mandibular canal and mandibular morphology by cone beam computed tomography in normal young people

Objective This research aimed to analyze the three-dimensional position of mandibular canal (MC) and mandibular morphology of normal young males and females by using data from cone beam computed tomography (CBCT), as well as to provide an anatomical basis for clinical surgery of the mandible. MethodsNormal occlusion and CBCT scans of 29 normal young people were conducted. InVivo 5 software was used to reconstruct the mandible, anchor the points, and measure the jaw shape and three-dimensional course of MC. All measurements were analyzed with SSPS 17.0 software. Results The MC lingual bone cortex was thinner than the MC buccal bone cortex, and the distance of the MC to the buccal bone cortex gradually increased. However, the distance of the MC to the tongue bone cortex and alveolar crest gradually decreased from proximal to distal. In addition, the distance of the MC to the mandibular lower margin was minimal at the first molar and reached the maximum at the second premolar. No significant difference was observed among the heights, widths, and thicknesses of the left and right sides of the cortical bone of the mandibular body cross sections. From the midline to the farthest point, the height and lower one-third thickness of the lingual cortical bone of the mandibular body cross sections gradually decreased, whereas the width of the upper cross section and upper one-third thickness of the buccal cortical bone gradually increased. Significant difference was observed in some measured values. ConclusionAfter MC enter into the mandibular foramen, it moved away from the lingual to the buccal bone but gradually returned to the lingual bone; its general course is closer to the lingual bone. The mandibles of males are thicker than those of females. CBCT can accurately display the course of MC and its relationship with the surrounding structures.