The significance of the anatomy of the skull base for mechanical modelling: a comparative study

The present paper aims at analysing the significance of the anatomical structures of the human skull base for mechanical modelling. Three different Finite-Element (FE)-models of the human neurocranium were developed. The most complex model (1242 solid cuboid elements) contains holes and spaces functionally simulating the foramina and fissures and additional element layers for the inner relief of the skull base (petrous temporal and sella). Of the less complex models, one (1256 solid cuboid elements) includes only the 3 cranial fossae, while the other (400 solid cuboid elements) represents a rotationally symmetrical ellipsoid with a hole for the foramen magnum. Two linear static loadcases, one with a transverse loading direction (pressure of 250 kg on the left temporal surface, bearing on the right temporal surface) and the other with a sagittal loading direction (pressure of 250 kg on the frontal surface, bearing on the occipital surface) were computed. The loadcase analyses show, qualitatively and quantitatively, similar equivalent von Mises stress values and distributions in the two more complex models while the elementary geometric model leads to significantly different absolute stress values and distributions. The results of the most complex model are highly compatible with experimental observations on transverse and sagittal fractures of the skull base.