Skull Thickness Morphing for an Age and Sex Specific FE Model of the Skull

Skull deformation is believed to be a contributing factor in traumatic brain injury (TBI). Furthermore, skull thickness is thought to be an important factor governing deformation of the skull and its susceptibility to fracture. Although many studies have been done to understand the mechanisms of brain injury and skull fracture, the majority of the cadaveric and finite element (FE) modeling efforts are comprised of older males and 50th percentile male skulls, respectively, which do not accurately represent the population as a whole. This study employed a set of skull table thickness regressions defined at homologous landmarks on the skull which were calculated from 123 pre-existing head CT scans (ages 20-100) using a cortical density-based algorithm. A method was developed to morph the Global Human Body Models Consortium (GHBMC) 50th percentile male skull model to age and gender specific geometries based on the full thickness regressions using a Thin Plate Spline algorithm. A quantitative measure of morphing error was devised and measured using the morphed and desired full thickness values at the homologous landmark locations. This methodology can be used to create gender and age-specific FE models of the skull and will ultimately be used to understand the relationship between cortical thickness, skull deformation, and head injury.