Tetrahedral mass spring model for fast soft tissue deformation

Abstract

Maxillofacial surgery treats abnormalities of the skeleton of the head. Skull remodelling implies osteotomies, bone fragment repositioning, restoratio'n of bone defects, inserting implants, .... Recently, the use of 3D image-based surgery planning systems is more and more accepted in this field. Although the bone-related planning concepts and methods are maturing, prediction of soft tissue deformation needs further fundamental research. In this paper we present a tetrahedral soft tissue model that can be used in a surgery planning system to predict soft tissue changes due to skeletal changes. Our model consists of mass points connected by springs. We propose a way to directly calculate the deformation of the model due to external changes. To achieve fast calculations we take advantage of the fact that most deformations are local and we compare our results with pre-computed reference models, to prove the accuracy of our model. © Springer-Verlag Berlin Heidelberg 2003.