Ogawa Takahiro, Osato Shigeo, Shishido Yuichi, Okada Michio, Misaki Kimiharu
Department of Histology, The Nippon Dental University School of Life Dentistry, Tokyo, Japan.
J Oral Implantol. 2012 Jun;38(3):203-10. doi: 10.1563/AAID-JOI-D-09-00143. Epub 2010 Aug 16.
Analysis of dental panoramic radiographs (DPRs) is an indispensable diagnostic tool for dental implants both pre and post operation. Many studies on linear and angular morphometry of the mandibular body have been conducted, but those on the mandibular ramus have not yet been reported. The purpose of this study was to investigate the differences in the morphometric parameters of the mandibular ramus between high and low gonial angles (GAs) on DPRs as well as between genders, and to determine the relationships between GA and variables of the mandibular ramus morphometry. The DPRs of 156 dentate subjects (78 for each gender) with more than 15 teeth present, a mean age of 49.54 years, and a mean number of teeth of 26.20 were examined. The films were divided into the following 2 groups of GA: less than 120° (low gonial angle, LGA) and more than 125° (high gonial angle, HGA) in both the right and left sides. The parameters for Ar'-Go, MaF-Go, RW, and RD in the LGA group were significantly larger than those in the HGA group in both men and women, but that for the ramus angle (RA) was significantly smaller in the LGA group than in the HGA group. Significant gender differences in the 2 GA groups were recognized with respect to the Ar'-Go, MaF-Go, RW, and RD parameters. Significant negative low and moderate correlations were found between GA and the Ar'-Go, MaF-Go, RW, and RD variables, whereas significant positive low correlation was found between GA and the RA variable. Within the limits of this study, the analysis of the mandibular ramus morphometry on DPRs in terms of GA size and gender was found to be useful for devising a highly predictive and strategic plan for implant-supported oral rehabilitation.
口腔全景片（DPRs）分析是种植牙手术前后不可或缺的诊断工具。关于下颌骨体部的线性和角度形态测量已经开展了许多研究，但关于下颌支的研究尚未见报道。本研究的目的是调查口腔全景片上下颌角（GAs）高低不同以及不同性别之间下颌支形态测量参数的差异，并确定下颌角与下颌支形态测量变量之间的关系。对156例有15颗以上牙齿、平均年龄49.54岁、平均牙数26.20颗的有牙受试者（男女各78例）的口腔全景片进行了检查。胶片按以下下颌角两组划分：左右两侧均小于120°（低下颌角，LGA）和大于125°（高下颌角，HGA）。在LGA组中，无论男性还是女性，Ar'-Go、MaF-Go、RW和RD的参数均显著大于HGA组，但LGA组的下颌支角（RA）显著小于HGA组。在Ar'-Go、MaF-Go、RW和RD参数方面，两个下颌角组存在显著的性别差异。在下颌角与Ar'-Go、MaF-Go、RW和RD变量之间发现显著的低和中度负相关，而在下颌角与RA变量之间发现显著的低正相关。在本研究的范围内，发现根据下颌角大小和性别对口腔全景片上的下颌支形态测量进行分析，有助于制定高度预测性和战略性的种植体支持口腔修复计划。
