Effect of Facial Asymmetry on 2-Dimensional and 3-Dimensional Cephalometric Measurements
Effect of Facial Asymmetry on 2-Dimensional and 3-Dimensional Cephalometric Measurements
复制标题
DOI：
10.1016/j.joms.2010.10.046
复制
发表时间：
2011-03-01
影响因子：
1.9
通讯作者：
Teichgraeber, John F.
中科院分区：
文献类型：
--
作者：
Gateno, Jaime;Xia, James J.;Teichgraeber, John F.
目的：验证面部对称对二维（2D）和三维（3D）头颅测量的影响。方法：首先建立首选对称脸的基线模型。它包括一套常用的头颅测量标志。选择7个头颅测量值进行测试。它们中的每一个都代表了一组不同的几何条件，这些几何条件与被测量的几何参数、所涉及的元素和测量类型有关。他们作为对照组。然后对基线模型进行修改，模拟10种不同的不对称模型，其中6种为上颌不对称模型，4种为下颌不对称模型。对10个不对称模型中的每一个模型再次使用相同的7头测量分析。他们作为实验组。结果：将测量结果制成表格并进行比较。对于形状的测量，二维头测测量由于横摇和偏航不对称而失真，而三维相同的测量则没有。对于尺寸的测量，二维测量也会被偏航扭曲，但不会被横摇扭曲，而三维测量也不会被扭曲。对于位置的测量，结果是相反的。二维头位测量结果无畸变，而三维测量结果均有畸变。值得注意的是，线性测量的畸变幅度比角度测量大得多。最后，定向测量，二维和三维测量都被不对称扭曲，尽管三维测量的扭曲程度更大。结论：本研究证实了面部不对称影响二维和三维头颅测量的假设。研究还表明，不对称对头颅测量的影响取决于被测量的几何参数（即形状、大小、位置或方向）。(C) 2011中华口腔颌面外科杂志[J] .中华口腔颌面外科杂志，69 (6):655-662,2011
Purpose: To test the hypothesis that facial symmetry affects both 2-dimensional (2D) and 3-dimesional (3D) cephalometric measurements.Methods: A baseline model of a preferred symmetrical face was first constructed. It consisted of a set of commonly used cephalometric landmarks. Seven cephalometric measurements were selected for testing. Each of them represented a different set of geometrical conditions related to the geometric parameters being measured, the elements involved, and the type of measurements. They served as a control group. The baseline model was then modified to simulate 10 different asymmetric models, 6 with maxillary asymmetries and 4 with mandibular asymmetries. The same 7 cephalometric analysis were utilized again on each of the 10 asymmetric models. They served as an experimental group.Results: The resulted measurements were tabulated and compared. For the measurements of shape, the 2D cephalometric measurement was distorted by roll and yaw asymmetries, while the same measurement in 3D was not. For the measurements of size, the 2D measurement was also distorted by yaw, but not by roll, while again this measurement in 3D was not distorted. For measurements of position, the results were reversed. The 2D cephalometric measurements of position were not distorted, while all measurements in 3D were distorted. Of note, the magnitude of the distortion was much larger for the linear measurement than angular measurement. Finally, measurements of orientation, both 2D and 3D measurements were distorted by asymmetry, although the magnitude of the distortion was larger for the 3D measurements.Conclusion: This study confirmed the hypothesis that facial asymmetry affects both 2D and 3D cephalometric measurements. It also demonstrated that the effects of asymmetry on cephalometric measurements depend on the geometric parameter being measured (ie, shape, size, position, or orientation). (C) 2011 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 69:655-662, 2011