Asymmetry Quantification and Contour Analysis on Patients with Facial Bone Deformities

• Main Authors: Yu-XinZhang, 張譽馨
• Other Authors: Jing-Jing Fang
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/38769631458038334893

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 101 === The voxel-based symmetry quantification is applicable in symmetry-like objects with irregular morphology. Succeeded from this voxel-based methodology[1, 2], this study further investigates its limitations, that is, the condition that induces the optimal symmetry plane of a symmetry-like object, deflecting from the expected location. By introducing deformation simulation, the response of the optimal symmetry ratio and optimal symmetry plane to the gradually enlarging asymmetrical structure can be investigated. When the size of the deformation exceeds a specific threshold, the optimal symmetry plane deviates from the expected position, the optimal symmetry ratio drops dramatically, and in turn the limitations of the symmetry evaluation methodology are reflected. Moreover, this research concentrating on the craniofacial complex purposes contour-based analysis to inspect the symmetry of the mandibular contour. Taking advantages of the mid-face optimal symmetry plane and Frankfort-Horizontal plane to define the canonical orientation, the frontal and submental mandibular contours are extracted to be analyzed in their symmetry on the projection planes of perception, and so as to complement the deficiency in the voxel-based approach. Mandibular asymmetry quantification is thus available by applying the optimal symmetry planes to contour-based methodology and the variations in morphology of the mandibular bilateral contours are visualized. Cooperation of the voxel-based and contour-based symmetry approaches masks the jaw asymmetry quantification more comprehensive.