Mixed Facial Deforming Technology Based on Volumetric Laplacian Deformation and Mass-Spring Model
In oral and maxillofacial surgery, the relationship between teeth movement and deformation of gingiva and face should be considered before clinical treatment. The digital prediction of facial deformation has implications for this research. In this study, a servo system composed of teeth, gingiva and face is conducted, and a mixed deformation method based on volumetric Laplacian deformation and mass-spring model is proposed. Firstly, the model is pre-treated to extract a suitable 3D model and intermodel scope before the calculation of deformation. Model registration is investigated based on curvature Hausdorff distance, and scope extraction uses ray-sampling and surface projection. Secondly, tetrahedral mesh generation is performed on the soft tissue models by using the constrained Delaunay tetrahedralisation. Finally, the volumetric Laplacian deformation and mass-spring model are analyzed based on tetrahedral mesh. In the experiments, gingival tissue model deformation is constructed by using volumetric Laplacian deformation and facial soft tissue model deformation based on the combined driven by the dental crown and gingival models was performed by adopting the mass-spring model of tetrahedral mesh. Experimental results with different parameters showed that facial soft tissue and gingival soft tissue deformations basically corresponded to the actual deformation of tissues in tooth movement.