Fujimura Kazuma, Segami Natsuki, Kobayashi Susumu
Department of Oral and Maxillofacial Surgery, Kanazawa Medical University, 1-1 Uchinada, Kahoku-gun, Ishikawa 920-0293, Japan.
J Oral Maxillofac Surg. 2006 Mar;64(3):384-9. doi: 10.1016/j.joms.2005.11.009.
The present study was performed to determine the variations in anatomical features of the ramus and the course of the maxillary artery to reduce the risk of injury during intraoral vertico-sagittal ramus osteotomy (IVSRO).
The locations and sizes of anatomical features of the medial aspect of mandibular rami were measured in 94 bilateral sides of 47 dry mandibles as a control group, and the results were compared with 3-dimensional computed tomography images of 44 sides of 22 patients with prognathism. We also dissected 12 sides of 6 mandibles from cadavers in a simulated IVSRO procedure to determine the course of the maxillary artery near the medial aspect of the ramus.
In the dry mandibles and patients with prognathism, the mandibular foramen was located slightly posterior to the center of the width of the mandibular ramus, and the lingula tip was located about one third the distance from the sigmoid notch to the inferior border of the ramus. The distance from the lateral margin of the mandibular foramen to the lateral surface of the mandibular ramus ranged from 3.1 to 4.4 mm. However, these distances showed various ranges. In the mandibles from Asian cadavers, the maxillary artery approached close to the ramus and passed lateral to the lower head of the lateral pterygoid muscle.
The position of the mandibular foramen in rami varies among individuals and, therefore, should be confirmed preoperatively on axial CT images. In addition, the maxillary artery approaches close to the medial aspect of the sigmoid notch in many cases. Therefore, the medial aspect from the sigmoid notch should be exposed carefully in the IVSRO procedure to avoid damaging the maxillary artery.
进行本研究以确定下颌支的解剖特征变化以及上颌动脉的走行，以降低口内垂直矢状劈开下颌支截骨术（IVSRO）期间的损伤风险。
在47具干燥下颌骨的94个双侧下颌支内侧测量解剖特征的位置和大小作为对照组，并将结果与22例凸颌患者的44侧三维计算机断层扫描图像进行比较。我们还在模拟IVSRO手术中对6具尸体的12侧下颌骨进行解剖，以确定上颌动脉在靠近下颌支内侧的走行。
在干燥下颌骨和凸颌患者中，下颌孔位于下颌支宽度中心稍后方，舌骨尖位于从乙状切迹到下颌支下缘距离的约三分之一处。下颌孔外侧缘到下颌支外侧表面的距离为3.1至4.4毫米。然而，这些距离显示出不同范围。在亚洲尸体的下颌骨中，上颌动脉靠近下颌支并从翼外肌下头外侧通过。
下颌支中下颌孔的位置因人而异，因此术前应在轴向CT图像上确认。此外，在许多情况下，上颌动脉靠近乙状切迹内侧。因此，在IVSRO手术中应小心暴露乙状切迹内侧，以避免损伤上颌动脉。
