Department of Prosthodontics and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Suita, Japan.
Department of Oral and Maxillofacial Radiology, Osaka University Graduate School of Dentistry, Suita, Japan.
J Prosthodont. 2019 Jan;28(1):e426-e430. doi: 10.1111/jopr.12598. Epub 2017 Sep 15.
To establish the accuracy of measuring the gonial angle on an orthopantomogram (GAO), as defined by the anatomic relationship between the inferior and posterior borders of the mandible. Furthermore, to examine the relationship between GAO and maximum occlusal force (MOF) in the premolar and molar regions of healthy young adults.
Orthopantomograms of dry mandibles were obtained in three orientations in the sagittal plane, to represent variation in image acquisition in clinical settings. The GAO was measured using image-processing software, and reliability was analyzed using the intraclass correlation coefficient. Then, GAO, MOF, gender, and body mass index (BMI) were measured in a cohort of healthy young adult volunteers. MOF was measured using an Occlusal Force Meter GM 10 device. The relationships between GAO, MOF, sex, and BMI were examined using the Pearson correlation coefficient and multiple regression analysis.
In five dry mandibles, there was a high correlation between the GAOs measured in the different orientations (p < 0.001). In 58 healthy volunteers (31 women and 27 men, mean age 24.6 years), the mean GAO was 123.3° ± 7.5°. The mean MOFs at the first premolar, second premolar, and first molar teeth were 256.4 N ± 128.3 N, 319.0 N ± 171.7 N, and 487.5 N ± 227.2 N, respectively. Men had significantly greater MOF than women at all teeth. The GAO was significantly inversely correlated with MOF at the second premolar (r = -0.376, p = 0.005) and first molar teeth (r = -0.479, p < 0.001). Multiple regression analysis showed that GAO was a significant explanatory factor for MOF at the second premolar and first molar teeth (p = 0.012 and 0.001, respectively).
GAOs were measured accurately on the orthopantomograms taken in this study and were a reliable predictor of MOF between the second premolar and first molar teeth. A smaller GAO was associated with a greater MOF at the second premolar and first molar teeth.
通过研究下颌骨下后缘与下颌下缘之间的解剖关系，来确定在全景片中测量下颌角（GAO）的准确性。此外，还探讨了健康年轻成年人前磨牙和磨牙区 GAO 与最大咬合力（MOF）之间的关系。
本研究获得了三组干下颌骨的矢状位全景片，以代表临床影像采集的变化。使用图像处理软件测量 GAO，并使用组内相关系数分析可靠性。然后，在健康年轻志愿者的队列中测量 GAO、MOF、性别和体重指数（BMI）。使用 Occlusal Force Meter GM 10 设备测量 MOF。使用 Pearson 相关系数和多元回归分析检验 GAO、MOF、性别和 BMI 之间的关系。
在五例干下颌骨中，不同方位测量的 GAO 之间具有高度相关性（p<0.001）。在 58 名健康志愿者（31 名女性和 27 名男性，平均年龄 24.6 岁）中，平均 GAO 为 123.3°±7.5°。第一前磨牙、第二前磨牙和第一磨牙的平均 MOF 分别为 256.4 N±128.3 N、319.0 N±171.7 N 和 487.5 N±227.2 N。男性在所有牙齿上的 MOF 均显著大于女性。GAO 与第二前磨牙（r=-0.376，p=0.005）和第一磨牙（r=-0.479，p<0.001）的 MOF 呈显著负相关。多元回归分析表明，GAO 是第二前磨牙和第一磨牙 MOF 的显著解释因素（p=0.012 和 0.001）。
本研究中在全景片上测量的 GAO 准确，是第二前磨牙和第一磨牙 MOF 的可靠预测因子。较小的 GAO 与第二前磨牙和第一磨牙的较大 MOF 相关。
