Dental template and parametric dental models are important tools for various applications in digital dentistry. However, constructing an unbiased dental template and accurate parametric dental models remains a challenging task due to the complex anatomical and morphological dental structures and also low volume ratio of the teeth. In this study, we develop an unbiased dental template by constructing an accurate dental atlas from CBCT images with guidance of teeth segmentation. First, to address the challenges, we propose to enhance the CBCT images and their segmentation images, including image cropping, image masking and segmentation intensity reassigning. Then, we further use the segmentation images to perform co-registration with the CBCT images to generate an accurate dental atlas, from which an unbiased dental template can be generated. By leveraging the unbiased dental template, we construct parametric dental models by estimating point-to-point correspondences between the dental models and employing Principal Component Analysis to determine shape subspaces of the parametric dental models. A total of 159 CBCT images of real subjects are collected to perform the constructions. Experimental results demonstrate effectiveness of our proposed method in constructing unbiased dental template and parametric dental model. The developed dental template and parametric dental models are available at https://github.com/Marvin0724/Teeth_template.
翻译:牙科模板和参数化的牙齿模型是数字牙科的各种应用中的重要工具。然而,由于复杂的解剖和形态牙齿结构以及牙齿体积低的比例,构建一个无偏的牙科模板和精确的参数化牙齿模型仍然是一个具有挑战性的任务。在本研究中,我们通过CBCT图像的牙齿分割,构建精确的牙齿图谱来开发无偏牙科模板。首先,为了解决这些问题,我们提出了增强CBCT图像和其分割图像的方法,包括图像剪裁,图像掩膜和分割强度重新分配。然后,我们进一步使用分割图像与CBCT图像进行配准以生成精确的牙齿图谱,从而可以生成无偏的牙科模板。通过利用无偏的牙科模板,我们通过估算牙齿模型之间的点到点对应关系,并使用主成分分析来确定参数化牙齿模型的形状子空间,构建参数化牙齿模型。共收集了159张真实受试者的CBCT图像进行构建。实验结果证明了我们提出的构建无偏牙科模板和参数化牙齿模型的方法的有效性。已经在https://github.com/Marvin0724/Teeth_template上提供了开发的牙科模板和参数化牙齿模型。