Nanjing Stomatological Hospital, Medical School of Nanjing University, 210008, Nanjing, China.
Department of Orthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, 210008, Nanjing, China.
Arch Oral Biol. 2021 Jul;127:105157. doi: 10.1016/j.archoralbio.2021.105157. Epub 2021 May 14.
To use cone beam computed tomography (CBCT) scans to analyze mandibular symmetry, the occlusal plane and their correlations in patients with high-angle skeletal class III malocclusion and jaw deformity.
Reconstructed images simulated of CBCT data of 20 adult patients with high-angle skeletal class III malocclusion and jaw asymmetry (Experimental group) and 20 adult patients of skeletal class I with normal faces (Control group) were measured with a three-dimensional (3D) geometric morphological measurement system. Related landmarks, lines and planes were marked and relevant distances and angles of 3D craniofacial structures were measured. The Student t-test was performed to assess symmetry. With the help of the Pearson correlation and Linear regression, we explored the correlations and other relationships among them.
Compared with control group, the symmetrical differences in experimental group were concentrated in condyle, coracoid process, mandibular angle, mandibular first molar area and the chin (P < 0.05). A strong positive correlation was found between the degree of mandibular deviation and the inclination of the occlusal plane in the coronal position (r = 0.860, P < 0.001) and a linear relationship between them was found: Y = 1.300 + 0.419X (the inclination of occlusal plane was Y, and the mandibular deviation was X).
Certain characteristics of mandibular symmetry and the occlusal plane were found in patients with high-angle skeletal class III malocclusion and jaw asymmetry. These findings provide references for doctors to pay attention to the degree and location of mandibular asymmetry and to determine the occlusal plane.
利用锥形束 CT（CBCT）扫描分析高角骨骼 III 类错颌畸形伴颌骨畸形患者的下颌对称性、咬合平面及其相关性。
对 20 例高角骨骼 III 类错颌畸形伴颌骨不对称的成年患者（实验组）和 20 例骨骼 I 类、面型正常的成年患者（对照组）的 CBCT 数据进行三维（3D）几何形态学测量系统的重建图像模拟。对相关标志点、线和平面进行标记，并测量 3D 颅面结构的相关距离和角度。采用 Student t 检验评估对称性。采用 Pearson 相关和线性回归分析探讨它们之间的相关性和其他关系。
与对照组相比，实验组的对称性差异主要集中在下颌髁突、喙突、下颌角、下颌第一磨牙区和颏部（P<0.05）。在冠状位上，下颌偏斜程度与咬合平面倾斜度之间存在很强的正相关（r=0.860，P<0.001），且呈线性关系：Y=1.300+0.419X（其中咬合平面倾斜度为 Y，下颌偏斜程度为 X）。
高角骨骼 III 类错颌畸形伴颌骨不对称患者的下颌对称性和咬合平面存在一定特征。这些发现为医生在确定咬合平面时注意下颌不对称的程度和位置提供了参考。
