Finite Element Model of the Face Soft Tissue for Computer-assisted Maxillofacial Surgery

In orthognatic surgery, patient mandible and maxilla are repositioned to correct face dismorphosis due to congenital malformation or traumatism. An important issue is to evaluate the consequences of these bone repositioning on the face soft tissue, in order to predict the post-operative aesthetic aspect of the patient. This problem is addressed using a biomechanical model of the patient skin tissue. A generic 3D Finite Element model of the face is presented, integrating skin layers and muscles with specific mechanical properties. This generic model is then automatically deformed to fit the patient morphology, using an elastic registration algorithm. The elements irregularities arising from the registration are automatically corrected. Therefore, a Finite Element model of each patient is available to simulate the face soft tissue deformation resulting from bone repositioning.