Kane A A, Lo L J, Chen Y R, Hsu K H, Noordhoff M S
Department of Plastic and Reconstructive, Chang Gung Memorial Hospital, Taipei, Taiwan.
Plast Reconstr Surg. 2000 Oct;106(5):1162-74; discussion 1175-6. doi: 10.1097/00006534-200010000-00029.
This study was undertaken to quantify the path of the inferior alveolar nerve in the normal human mandible and in the mandibles of patients presenting for cosmetic reduction of the mandibular angles. The goals were: (1) to provide normative information that would assist the surgeon in avoiding injury to the nerve during surgery; (2) to characterize gender differences in the normal population; and (3) to compare the course of the nerve in the normal population to its course in a group of patients who presented with a complaint of "square face." The study was based upon the computerized tomographic scans of 10 normal patients (six men, four women) and 8 patients (all women) complaining of "square face." Using AnalyzePC 2.5 imaging software, the mandibles were segmented and the position of the nerve was recorded within its osseous canal in the mandibular ramus on each axial slice in which it was identifiable. Distances were calculated between the nerve and the anterior, posterior, lateral, and medial cortices. The positions of the lateral ramus prominence and the lowest point on the sigmoid notch were also recorded. The position of the mental foramen was recorded in relation to the nearest tooth, and the three-dimensional surface distances from the foramen to the alveolar bone, the inferior border of the mandible, and the mandibular symphysis were determined. The distances from the entrance of the nerve into the mandible to the lateral ramus prominence and the lowest point on the sigmoid notch were calculated. Summary statistics were obtained, comparing differences in gender. The nerve was identifiable in each ramus over a mean distance of 12.7 mm. On average, the lateral ramus prominence was 0.3 mm higher on the caudad-cephalad axis than the point at which the nerve entered the bone, whereas the location of the lowest point on the sigmoid notch was 16.6 mm above the nerve. The average distances from the nerve to the anterior, posterior, medial, and lateral cortices were 11.6, 12.1, 1.8, and 4.7 mm, respectively. Gender differences were significant for all of these except the medial cortex to nerve distance. On average, the mental foramen exited the body of the mandible immediately below the second premolar and the average surface distances from the foramen to the symphysis, the most cephalad alveolar bone, and the inferior border of the body were 30.9, 14.2, and 19.3 mm, respectively. With regard to the patients presenting for mandibular angle reduction, there were a few statistically significant but small scalar differences from normal controls.
本研究旨在量化正常人类下颌骨以及因下颌角美容缩小而就诊患者的下颌骨中下牙槽神经的走行路径。目标如下：（1）提供规范性信息，以协助外科医生在手术过程中避免损伤神经；（2）描述正常人群中的性别差异；（3）比较正常人群中神经的走行与一组主诉为“方脸”患者的神经走行。该研究基于10名正常患者（6名男性，4名女性）和8名主诉“方脸”患者（均为女性）的计算机断层扫描图像。使用AnalyzePC 2.5成像软件，对下颌骨进行分割，并在神经可识别的每个轴向切片上记录其在下颌支骨管内的位置。计算神经与前、后、外侧和内侧皮质之间的距离。还记录了下颌支外侧突出部和乙状切迹最低点的位置。记录颏孔相对于最近牙齿的位置，并确定从颏孔到牙槽骨、下颌骨下缘和下颌联合的三维表面距离。计算神经进入下颌骨处到下颌支外侧突出部和乙状切迹最低点的距离。获得汇总统计数据，比较性别差异。在每个下颌支中，神经平均可识别的距离为12.7毫米。平均而言，下颌支外侧突出部在尾端-头端轴上比神经进入骨的点高0.3毫米，而乙状切迹最低点的位置在神经上方16.6毫米。神经到前、后、内侧和外侧皮质的平均距离分别为11.6、12.1、1.8和4.7毫米。除了内侧皮质到神经的距离外，所有这些距离的性别差异均具有统计学意义。平均而言，颏孔在下颌骨体部第二前磨牙正下方穿出，颏孔到下颌联合、最头端牙槽骨和下颌骨体下缘的平均表面距离分别为30.9、14.2和19.3毫米。对于因下颌角缩小而就诊的患者，与正常对照组相比，存在一些具有统计学意义但数值较小的差异。
