A jaw model for the study of the mandibular flexure taking into account the anisotropy of the bone

Knowledge of the complex biomechanical behaviour of the human mandible is of great importance in various clinical situations. The biomechanical and physical behaviour of mandibles have been investigated by different approaches. Some research have been done to evaluate the functional character of mandibles. Methods such as indirect measurement of deformations performed by intraoral appliances and by holographic interferometry have being employed. Other studies evaluated the mechanical properties and material parameters of small cubes of mandibles. One disadvantage of the experiments using strain gauges or holographic interferometry is the inability to determine strains at defined positions within the specimen. Additionally, research in biomechanics by these methods is limited to surface deformations and neither stresses nor dislocations can be measured. In the course of this study, we have investigated the mandibular flexure under mechanical loads using the results of a Finite Element Analysis (FEA). In order to obtain more accurate and realistic results, the bone anisotropy has being taken into account for the mathematical modelling of the jaw. The objective of this study was to establish a non-invasive procedure to predict precisely the complex biomechanical reactions of mandibles under mechanical loading. In order to achieve this aim, a comparison of the numerical data obtained with the experimental values of previous studies was performed. It showed a good correlation between in vitro measurements and mathematical modelling. Then the Finite Elements (FE) model was used to evaluate some mandibular movements (corporal approximation, dorsoventral shear, and corporal rotation in edentulous subjects). It is concluded that the applied procedure of generating the FE model is a valid and accurate non-invasive method to predict different parameters of the complex biomechanical behaviour of human mandibles.