Marklund M, Persson M
Department of Orthodontics, Faculty of Odontology, University of Umeå, Sweden.
Arch Oral Biol. 1988;33(6):391-4. doi: 10.1016/0003-9969(88)90195-1.
Two samples of individuals, a low-angle group and a high-angle group, were selected on the basis of the inclination of the lower border of their mandible, defined by the mandibular plane angle (ML/SNL) in profile radiographs. Apical root curvature of mandibular first and second premolars and molars on panoramic radiographs was compared between the two groups and related to mandibular morphology. In the low-angle group most teeth had more distally curved roots than in the high-angle group. Significant differences were found for the first premolars on both sides (p less than 0.001, p less than 0.05), the right second premolars (p less than 0.05) and the distal root of left first molars (p less than 0.05). Correlations were calculated between root curvature and two variables reflecting mandibular morphology, the mandibular plane angle and the gonial angle. The strongest associations were found between the first premolar roots and the gonial angle (rs = -0.75, p less than 0.001 and rs = -0.56, p less than 0.01, for right and left sides respectively). The association between mandibular morphology and root curvature is probably indirect, caused by tooth migration during root formation.
根据全景X光片中下颌平面角（ML/SNL）所定义的下颌骨下缘倾斜度，选取了两组个体样本，即低角组和高角组。比较了两组全景X光片中下颌第一、第二前磨牙及磨牙的根尖根曲率，并将其与下颌形态相关联。低角组中大多数牙齿的牙根向远中弯曲的程度高于高角组。两侧第一前磨牙（p<0.001，p<0.05）、右侧第二前磨牙（p<0.05）和左侧第一磨牙远中根（p<0.05）均存在显著差异。计算了根曲率与反映下颌形态的两个变量（下颌平面角和下颌角）之间的相关性。在前磨牙牙根与下颌角之间发现了最强的关联（右侧和左侧的rs分别为-0.75，p<0.001和rs = -0.56，p<0.01）。下颌形态与根曲率之间的关联可能是间接的，由牙根形成过程中的牙齿移动引起。
