A micromechanical multiscale model which estimates the elastic properties of cortical bone as a function of porosity and mineral content is presented. The steps of the model are divided into two main phases. In the first one, the elastic properties of the collagen fibril, collagen fiber and lamella are given. In the second phase, porosity is included in the lamella in the form of canaliculi, lacunae and Haversian canals, to provide the elastic properties of the osteonal tissue. Then, a symmetrization technique is used to estimate the transversely isotropic elasticity tensor of the osteon. Osteons are superimposed using a self-consistent scheme, and finally, the fluid filling the pores is included to estimate the elastic constants of the undrained cortical tissue. The main novelty of the model presented here is the possibility of varying the mineral content of bone, considering that mineralization begins from the inner levels, initially intrafibrillar and then interfibrillar. Correlations of the elastic properties of cortical bone obtained with this model on the one hand, and porosity and ash fraction on the other hand, are estimated.
A finite element model of the temporomandibular joint (TMJ) and the human mandible was fabricated to study the effect of abnormal loading, such as awake and asleep bruxism, on the articular disc. A quasilinear viscoelastic model was used to simulate the behaviour of the disc. The viscoelastic nature of this tissue is shown to be an important factor when sustained (awake bruxism) or cyclic loading (sleep bruxism) is simulated. From the comparison of the two types of bruxism, it was seen that sustained clenching is the most detrimental activity for the TMJ disc, producing an overload that could lead to severe damage of this tissue.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.