Anatomical and Dynamic Volume Spline Model Applied to Facial Soft Tissue

Ulusoy Parnas, İlkay
Akagündüz, Erdem
Yırcı, Murat
Biomechanical modeling of soft tissue is a complex problem for achieving realistic surgical simulations, surgical planning, and scientific analysis. In the literature, three categories of biomechanical models: spline based models, spring models, and finite element models (FEMs) are mainly used for dealing with this problem. Among these, spline based models offer relatively fast and realistic soft tissue simulations by utilizing both the spring and FEMs. In this paper, a new dynamic volume spline model for human face skin is proposed and the performance of our model is discussed by estimating the results of facial surgery of three different patients. Face models of the patients are obtained from 3D CT/MR scans by segmenting the skull, muscle, and skin layers. In these face models, the skull and the muscle layers are considered as the rigid boundary for the skin layer and the skin layer is modeled by our dynamic volume spline. The control points of the dynamic volume spline are localized masses with viscoelastic material properties (stiffness, damping, and mass). These parameters are computed from the skin material properties that were published in the literature. Once the face models are generated, facial surgery plannings are simulated. Infact, the pre‐surgery face models are modified according to the surgical plans and the estimated post‐surgery face models are compared with the actual post‐surgery face models. Moreover, in order to discuss the performance of our dynamic volume spline model, the same analyses are performed on the post‐surgery estimations of a conventional tool.