Fujita Atsushi, Shintani Satoru
*Medical staff of Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan; Department of Oral and Maxillofacial Surgery, School of Dentistry, Showa University, Tokyo, Japan. †Assistant Professor, Department of Oral and Maxillofacial Surgery, School of Dentistry, Showa University, Tokyo, Japan.
Implant Dent. 2015 Aug;24(4):402-6. doi: 10.1097/ID.0000000000000271.
The aims of this study were to use computed tomography (CT) imaging to determine the anatomical features of the mandibular body and ramus in Japanese subjects and to relate the findings to bone harvesting from the mandibular ramus.
The mandibles of 100 patients (28 males and 72 females) under dental implant treatment plan were observed on CT imaging (slice thickness, 0.625 mm). The linear distance between the superior aspect of the inferior alveolar nerve canal and the alveolar crest (distance A), the linear distance between the buccal aspect of the inferior alveolar nerve canal and the buccal cortical bone (distance B), the thickest width of the buccal cortical bone (distance C), and the thinnest width of the buccal cortical bone (distance D) were measured in the same coronal plane at 4 specific locations (section 1: the distal aspect of the first molar, section 2: the distal aspect of the second molar, section 3: the 10 mm distal aspect of the second molar, and section 4: the 15 mm distal aspect of the second molar).
In the measurement of distance A, the minimum section among the male subjects was section 2 (12.55 ± 3.00 mm), whereas among the females, the minimum section was section 3 (11.82 ± 2.85 mm). In the distance B measurements, the maximum value was at section 2 (males: 6.36 ± 1.33 mm, females: 6.32 ± 1.39 mm) and the minimum value was at section 4 (males: 3.85 ± 1.74 mm, females: 4.75 ± 1.47 mm). Regarding the distance C measurements, the values of all subjects ranged from 3.10 to 4.41 mm, and the distance D values were approximately 2 mm.
In Japanese patients, a rectangular piece of cortical bone up to 2 mm thickness may be harvested from the ramus, the length of the rectangular graft may approach 26 mm, and the height may be 10 mm for the safest harvesting from the mandibular ramus.
本研究的目的是使用计算机断层扫描（CT）成像来确定日本受试者下颌体和下颌支的解剖特征，并将这些发现与下颌支骨采集相关联。
对100例接受牙种植治疗计划的患者（28例男性和72例女性）的下颌骨进行CT成像观察（层厚0.625mm）。在下牙槽神经管上缘与牙槽嵴之间的线性距离（距离A）、下牙槽神经管颊侧与颊侧皮质骨之间的线性距离（距离B）、颊侧皮质骨的最厚宽度（距离C）以及颊侧皮质骨的最薄宽度（距离D），在4个特定位置的同一冠状平面上进行测量（第1节：第一磨牙远中面，第2节：第二磨牙远中面，第3节：第二磨牙远中10mm处，第4节：第二磨牙远中15mm处）。
在距离A的测量中，男性受试者的最小截面是第2节（12.55±3.00mm），而女性中最小截面是第3节（11.82±2.85mm）。在距离B的测量中，最大值在第2节（男性：6.36±1.33mm，女性：6.32±1.39mm），最小值在第4节（男性：3.85±1.74mm，女性：4.75±1.47mm）。关于距离C的测量，所有受试者的值在3.10至4.41mm之间，距离D的值约为2mm。
在日本患者中，可从下颌支获取厚度达2mm的矩形皮质骨块，矩形移植骨的长度可接近26mm，高度可为10mm，以便从下颌支进行最安全的采集。
