What happens between pure hydraulic and buckling mechanisms of blowout fractures?

Biomechanical investigation of naso-orbitoethmoid trauma by finite element analysis

“…We assumed von Mises stresses of 150 MPa for the yield criterion of bone in the skull. 10 According to the regulations of our Institutional Review Board, approval was not needed for this investigation.…”

Transient finite element analysis of a traumatic fracture of the zygomatic bone caused by a head collision

“…First the novel modelling approach of the skull was compared with modelling data used in earlier investigations 1,2,15 . In contrast to the skull model of NAGASAO et al which was divided into several triangular sheets with defined thicknesses 15,16 , the model in this study can smoothly follow the contours of the skull and represents the thicknesses of the bone layers realistically (Fig. 1B and C).…”

“…These properties were also used to represent the impactor according to AHMAD et al 1,2 . For the simplified skull model, which was utilized as an impactor in the collision study, a Young's modulus of 13,500 MPa, a density of 1.591 g/cm 3 and a Poisson's ratio of 0.32 were used based on the literature 8,15,16 (Table 1).…”

“…Cadaver studies can only deal with single questions and are limited by the availability of adequate cadaver specimens and the necessary equipment. FEA has been used in investigations on biomechanical simulation of isolated orbital wall fractures using defined objects to hit the infraorbital rim 15,16 . The results of these studies are supported by the findings of several biomechanical experiments concerning orbital wall fractures 1,2,27,28 and are confirmed by a case study 6 .…”

“…simulating the whole trauma with smooth transition of all steps), which allows simulating the entire incident without additional calculation to determine the impact force and impact time 16,27 . This type of analysis is more suitable for representing the realistic behaviour of the skull during trauma, as the effect of the viscoelastic response of bone due to a time dependent load has already been investigated for the upper limb in an experimental study 22 .…”