PDF(Pubmed)
Abstract：
BACKGROUND: An accurate identification of mandibular asymmetries is required by modern orthodontics and orthognathic surgery to improve diagnosis and treatment planning of such deformities. Although craniofacial deformities are very frequent pathologies, some types of asymmetries can be very difficult to assess without the proper diagnostic tools. The purpose of this study was to implement the usage of three-dimensional (3D) segmentation procedures to identify asymmetries at the mandibular level in adult patients with different vertical and sagittal patterns where the asymmetries could go unnoticed at the observational level.
METHODS: The study sample comprised 60 adult patients (33 women and 27 men, aged between 18 and 60 years). Subjects were divided into 3 sagittal and vertical skeletal groups. CBCT images were segmented, mirrored and voxel-based registered with reference landmarks using ITK-SNAP® and 3DSlicer® software\'s. 3D surface models were constructed to evaluate the degree of asymmetry at different anatomical levels.
RESULTS: There was a degree of asymmetry, with the left hemimandible tending to contain the right one (0.123 ± 0.270 mm (CI95% 0.036-0.222; p < 0.001). Although the subjects under study did not present significant differences between mandibular asymmetries and their sagittal or vertical skeletal pattern (p = 0.809 and p = 0.453, respectively), a statistically significant difference has been found depending on the anatomical region (p < 0.001; CI95%=1.020-1.021), being higher in the condyle, followed by the ramus and the corpus.
CONCLUSIONS: Although mandibular asymmetries cannot be correlated with vertical and sagittal skeletal patterns in symmetric patients, knowledge about 3D segmentation procedures and color maps can provide valuable information to identify mandibular asymmetries.
METHODS: The study sample comprised 60 adult patients (33 women and 27 men, aged between 18 and 60 years). Subjects were divided into 3 sagittal and vertical skeletal groups. CBCT images were segmented, mirrored and voxel-based registered with reference landmarks using ITK-SNAP® and 3DSlicer® software\'s. 3D surface models were constructed to evaluate the degree of asymmetry at different anatomical levels.
RESULTS: There was a degree of asymmetry, with the left hemimandible tending to contain the right one (0.123 ± 0.270 mm (CI95% 0.036-0.222; p < 0.001). Although the subjects under study did not present significant differences between mandibular asymmetries and their sagittal or vertical skeletal pattern (p = 0.809 and p = 0.453, respectively), a statistically significant difference has been found depending on the anatomical region (p < 0.001; CI95%=1.020-1.021), being higher in the condyle, followed by the ramus and the corpus.
CONCLUSIONS: Although mandibular asymmetries cannot be correlated with vertical and sagittal skeletal patterns in symmetric patients, knowledge about 3D segmentation procedures and color maps can provide valuable information to identify mandibular asymmetries.
摘要：
背景：现代正畸和正颌外科需要准确识别下颌不对称性，以改善此类畸形的诊断和治疗计划。虽然颅面畸形是非常常见的病理，如果没有适当的诊断工具，某些类型的不对称性可能很难评估。这项研究的目的是使用三维（3D）分割程序来识别具有不同垂直和矢状模式的成年患者下颌水平的不对称性，其中不对称性在观察水平上可能不会被注意到。
方法：研究样本包括60名成年患者（33名女性和27名男性，年龄在18至60岁之间)。受试者分为3个矢状和垂直骨骼组。CBCT图像被分割，使用ITK-SNAP®和3DSlicer®软件与参考地标进行镜像和基于体素的配准。构建3D表面模型以评估不同解剖水平的不对称程度。
结果：存在一定程度的不对称性，左侧半可食倾向于包含右侧（0.123±0.270mm（CI95％0.036-0.222；p<0.001）。尽管所研究的受试者在下颌不对称性及其矢状或垂直骨骼模式之间没有显着差异（分别为p=0.809和p=0.453），根据解剖区域发现了统计学上的显着差异（p<0.001；CI95％=1.020-1.021），髁更高，其次是ramus和语料库。
结论：尽管在对称患者中下颌不对称性与垂直和矢状骨骼模式不能相关，有关3D分割程序和彩色图的知识可以提供有价值的信息来识别下颌不对称。
方法：研究样本包括60名成年患者（33名女性和27名男性，年龄在18至60岁之间)。受试者分为3个矢状和垂直骨骼组。CBCT图像被分割，使用ITK-SNAP®和3DSlicer®软件与参考地标进行镜像和基于体素的配准。构建3D表面模型以评估不同解剖水平的不对称程度。
结果：存在一定程度的不对称性，左侧半可食倾向于包含右侧（0.123±0.270mm（CI95％0.036-0.222；p<0.001）。尽管所研究的受试者在下颌不对称性及其矢状或垂直骨骼模式之间没有显着差异（分别为p=0.809和p=0.453），根据解剖区域发现了统计学上的显着差异（p<0.001；CI95％=1.020-1.021），髁更高，其次是ramus和语料库。
结论：尽管在对称患者中下颌不对称性与垂直和矢状骨骼模式不能相关，有关3D分割程序和彩色图的知识可以提供有价值的信息来识别下颌不对称。
