Finite element method for analysis of stresses arising in the skull after external loading in cranio-orbital...

The craniofacial skeleton remains not fully recognised as far as its mechanical resistance properties are concerned. Heretofore, the only available information on the mechanism of cranial bone fractures came from clinical observations, since the clinical evaluation in a living individual is practically impossible. It seems crucial to implement computer methods of virtual research into clinical practice. Such methods, which have long been used in the technical sciences, may either confirm or disprove previous observations. The aim of the study was to identify the areas of stress concentrations caused by external loads, which can lead to cranio-orbital fractures (COF), by the finite element method (FEM).

For numerical analysis, a three-dimensional commercially available geometrical model of the skull was used which was imported into software of FEM. Computations were performed with ANSYS 12.1 Static Structural module. The loads were applied laterally to the frontal squama, the zygomatic process and partly to the upper orbital rim to locate dangerous concentration of stresses potentially resulting in COF.

Changes in the area of force application revealed differences in values, quality and the extent of the stress distribution. Depending on the area of force application the following parameters would change: the value and area of stresses characteristic of COF.

The distribution of stresses obtained in this study allowed definition of both the locations most vulnerable to fracture and sites from which fractures may originate or propagate.