Lo Lun-Jou, Wong Fen-Hwa, Chen Yu-Ray
Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Taipei, Taiwan.
Ann Plast Surg. 2004 Jul;53(1):50-5. doi: 10.1097/01.sap.0000112282.94585.44.
Mandibular angle reduction is a popular contouring surgery in Asia. Avoidance of injury to the inferior alveolar nerve is crucial during these procedures. Anatomic data regarding the position of the nerve in the mandibular angle area are sparse. The purpose of this study was to use 3-dimensional computed tomographic data to evaluate the nerve in patients with prominent mandibular angles and to compare the nerve position with a normative group. A total of 28 female and 5 male adult patients who presented with a complaint of prominent angles or a "square-face" look, as well as 20 female and 22 male adult normal subjects were included, for a total of 150 hemimandibles for extraction of the inferior alveolar nerve. The nerve and the mandible were displayed. Point O was defined on the oblique line along the anterior cortex of ramus, where it intersected with a line extending from the alveolar arch. From the O point, linear distances were defined, including horizontal distances to the posterior cortex, oblique distances to the gonion, and the vertical distances to the inferior cortex. Mandibular width was defined as the distance between the 2 gonion points. Results demonstrated significant differences mainly in the oblique distances (ie, from the O point to the nerve [O1], from the nerve to the gonion [O2], and from the O point to the gonion [O1-O2]) in both female and male patients. The O2 distance was 23.69 mm versus 20.66 mm in women and 27.30 mm versus 23.28 mm in men (square face vs norm). The mandibular width was significantly larger in the male square-face patients, but the difference was not significant between the female groups. These results provide useful information for surgeons planning mandibular angle reduction. These findings suggest that the mandibular contouring procedure should be aimed at correcting regional osseous dysmorphology in the angle area and improving the relationship to the chin, rather than merely reducing the mandibular width.
下颌角缩小术在亚洲是一种流行的轮廓整形手术。在这些手术过程中，避免损伤下牙槽神经至关重要。关于下颌角区域神经位置的解剖学数据稀少。本研究的目的是使用三维计算机断层扫描数据评估下颌角突出患者的神经，并将神经位置与正常组进行比较。纳入了总共28名女性和5名男性成年患者，他们主诉下颌角突出或呈“方脸”外观，以及20名女性和22名男性成年正常受试者，共150个半侧下颌骨用于提取下牙槽神经。显示神经和下颌骨。点O定义在沿着下颌支前缘皮质的斜线上，该斜线与从牙槽弓延伸的线相交处。从O点开始，定义线性距离，包括到后皮质的水平距离、到下颌角的斜距离以及到下皮质的垂直距离。下颌宽度定义为两个下颌角点之间的距离。结果表明，女性和男性患者主要在斜距离（即从O点到神经[O1]、从神经到下颌角[O2]以及从O点到下颌角[O1 - O2]）上存在显著差异。女性的O2距离为23.69毫米，而正常女性为20.66毫米；男性的O2距离为27.30毫米，而正常男性为23.28毫米（方脸与正常）。男性方脸患者的下颌宽度明显更大，但女性组之间的差异不显著。这些结果为计划进行下颌角缩小术的外科医生提供了有用信息。这些发现表明，下颌轮廓整形手术应旨在纠正角区域的局部骨形态异常，并改善与下巴的关系，而不仅仅是减小下颌宽度。
