牙颌模型激光扫描数据与锥形束CT数据配准方法的精度比较

Accuracy of different registration methods for laser-scanned dental cast data and maxiUofacial cone-bean CT data

目的比较目前常用的4种配准方法配准牙颌区域三维表面数据和体数据的精度，为临床选择三维数据配准方法提供依据。方法采集1例下颌牙列完整的安氏I类错拾畸形患者牙颌区域锥形束cT体数据及其牙颌模型激光扫描表面数据，分别采用基于标志点配准的定位球心和解剖标志点配准方法，以及基于迭代最近点算法的局部特征区域和全局配准方法，对两种数据进行配准，利用三维测量软件的偏差分析功能计算配准误差，比较4种配准方法的配准精度。结果定位球心方法、解剖标志点方法、局部特征区域配准方法和全局配准方法的配准偏差分别为-（0．082±0．221）、-（0．104±0．218）、-（0．047±0．138）和-（0．025±0．129）mm。结论基于迭代最近点算法的两种配准法精度好于基于标志点配准的两种配准方法。同时，全局配准方法的精度略好于局部特征区域配准方法，定位球心方法的精度略好于解剖标志点方法。

Objective To evaluate the accuracy of four dominant methods of three-dimensional multisource data registration. Methods Laser-scanned dental model and maxillofacial cone-bean CT rebuilt model were collected for one orthodontic patient before treatment. Registration process was done based on locating spheres＇ center, anatomic landmarks, partial characteristic region and global data separately. The registration errors were detected by the function of Geomagic Studio 12. 0 software. A comparison of the registration accuracy among these four methods was done by analyzing mean error and standard deviation. Results The mean errors and standard deviations of methods of locating spheres＇ center, anatomic landmarks, partial characteristic region and global data were - （0. 082 ± 0. 221 ）, - （0. 104 ± 0.218）, - （0.047 ±0. 138） and - （0.025±0. 129） mm respectively. Conclusions ICP registration methods had better reliability than landmark methods. The global registration was more accurate than partial characteristic region registration and the locating spheres＇ center method was better than anatomic landmarks method.