应用国产DSC—Ⅰ型三维相机进行面部软组织测量的初步研究

Preliminary Study of Application of DSC-Ⅰ 3D Imaging System in Facial Soft Tissue Measurement

目的本研究旨在评价DSC-Ⅰ型三维相机进行面部软组织测量的可行性、精确性。方法随机选取无明显骨／牙性畸形，面形基本对称（肉眼观）的口腔医学学生20名，男女各半，使用DSC-Ⅰ型三维相机拍摄样本在自然头位下的三维相片，三个研究者分别进行三维定点测量，比较三次测量结果，评价三维定点的稳定性以及与实测相比的准确性。结果约80％的点在重复定点时的空间改变小于2mm，86％的三维测量项目的三次结果之间存在高度显著相关性，所选与实测比较的线距中只有Go-Me（下颌体长度）一项存在显著性差异。结论DSC-Ⅰ型三维软组织成像系统具有非侵人性、成像安全迅速、自动拼接重建三维影像、后处理步骤简便等特点，三维测量软件及其中的测量项目具有临床实用性，操作较简便，结果能以直观形式呈现，测量稳定性可满足临床需要。该系统不足在于取景范围偏小，边缘部位影像质量下降，并且由于需要相继两次曝光，如在此间隔所拍对象的位置和面部状态发生微小改变，也会影响影像的拼接整合，继而造成测量误差。

Objective To evaluate the feasibility and accuracy of Three Dimensional （3D） measurement in facial soft tissue using DSC -Ⅰ 3D Imaging System. Methods 3D images of 20 subjects were taken under Nature Head Position using DSC -Ⅰ. Thirty linear and angular measurements were performed on 3D images by 3 researchers independently. 7 linear measurements were also performed on faces of these subjects manually using a digital caliper with a linear resolution of 1/100mm at the meanwhile of taking 3D images. Variations were calculated and tested for statistical significance. Results Point registration variation in about 80% points was less than 2rnm. Significant correlation existed in 86% measurements performed by different researchers. Conclusion DSC -Ⅰ 3D Imaging System can produce vivid and accurate 3D images which could be used for 3D diagnosis clinically. The 3D measurement software was easy to use and the reliability of 3D measurements could meet the standard of clinical application. Further effort need to be made to improve the relative small field-of-view and the double exposure mode which would lead to errors resulted from the displacement of the imaging subject in the short exposure interval. （Supported by National Science Foundation of China, 30371558）