A clinically relevant viscoelastic FEA model of the mandible simulating the effect of a Herbst appliance

Abstract

As a powerful numerical solution to partial differential equations with sophisticated boundary conditions, Finite element analysis (FEA) has been vastly used to solve engineering problems. This tool also found to be useful in predicting load-strain patterns and biological failures in mechanics of dental applications as well. In orthodontics field, several studies addressed the benefits in use of FEM models to predict stresses and strains in jaws. These studies mostly considered only the linear elastic phase which corresponds to the immediate response of the bone to the loading during functions. On the other hand, it is the prediction of long-term stress and strain distributions that are useful for clinical purposes. Therefore, it is suggested in this study that the viscoelastic properties of the bone need to be incorporated in the analysis to render long-term stress and displacement patterns. In this research, for the first time to our knowledge, effects of viscoelasticity of the mandibular bone are incorporated into finite element analyses of force distribution and displacement of anatomical structures in response to a Herbst appliance. Our models clearly demonstrate how displacements of the mandible occur in accordance with distributions of force vectors.