IEEE Trans Biomed Eng. 2021 Feb;68(2):362-373. doi: 10.1109/TBME.2020.2990586. Epub 2021 Jan 20.
To estimate a patient-specific reference bone shape model for a patient with craniomaxillofacial (CMF) defects due to facial trauma.
We proposed an automatic facial bone shape estimation framework using pre-traumatic conventional portrait photos and post-traumatic head computed tomography (CT) scans via a 3D face reconstruction and a deformable shape model. Specifically, a three-dimensional (3D) face was first reconstructed from the patient's pre-traumatic portrait photos. Second, a correlation model between the skin and bone surfaces was constructed using a sparse representation based on the CT images of training normal subjects. Third, by feeding the reconstructed 3D face into the correlation model, an initial reference shape model was generated. In addition, we refined the initial estimation by applying non-rigid surface matching between the initially estimated shape and the patient's post-traumatic bone based on the adaptive-focus deformable shape model (AFDSM). Furthermore, a statistical shape model, built from the training normal subjects, was utilized to constrain the deformation process to avoid overfitting.
The proposed method was evaluated using both synthetic and real patient data. Experimental results show that the patient's abnormal facial bony structure can be recovered using our method, and the estimated reference shape model is considered clinically acceptable by an experienced CMF surgeon.
The proposed method is more suitable to the complex CMF defects for CMF reconstructive surgical planning.
为因面部创伤而患有颅颌面（CMF）缺陷的患者估算特定于患者的参考骨形状模型。
我们提出了一种使用创伤前常规肖像照片和创伤后头部计算机断层扫描（CT）扫描的自动面部骨骼形状估算框架，通过 3D 面部重建和可变形形状模型实现。具体来说，首先从患者的创伤前肖像照片重建三维（3D）面部。其次，使用基于训练正常受试者 CT 图像的稀疏表示构建皮肤和骨骼表面之间的相关模型。第三，通过将重建的 3D 面部输入相关模型，生成初始参考形状模型。此外，我们通过在自适应焦点可变形形状模型（AFDSM）的基础上，在初始估计形状和患者创伤后骨骼之间应用非刚性表面匹配，对初始估计进行细化。此外，还利用来自训练正常受试者的统计形状模型来约束变形过程，以避免过拟合。
使用合成和真实患者数据对所提出的方法进行了评估。实验结果表明，我们的方法可以恢复患者异常的面部骨结构，并且经验丰富的 CMF 外科医生认为所估计的参考形状模型在临床上是可以接受的。
该方法更适合用于 CMF 重建手术规划的复杂 CMF 缺陷。
