Age and gender-dependent bone density changes of the human skull disclosed by high-resolution flat-panel computed tomography

Abstract

Introduction: The objective of this article was to estimate the age at death in forensic or anthropologic applications based on human skull investigation. Sex-dependent differences were analyzed.

Methods: Digital, high-resolution, flat-panel-based volumetric computed tomography (eXplore Locus Ultra scanner) images (165,920) of 244 European human skulls-163 males, 81 females-were analyzed according to their radiological bone density, based on Hounsfield units (H) that are directly related to the x-ray attenuation of the scanned material. Data were collected by the Department of Forensic Medicine at the University Hospital Giessen and Marburg during 2007 and 2008. Correlation analysis was used for data description.

Results: Human skull density estimates are widely scattered as a function of age for both sexes. Male skull bone density remains constant during lifetime, whereas female skull bone density decays slowly from approximately 20 years onwards.

Conclusions: Bone density decay only theoretically provides a new method to determine age at death for adult females. Due to the scattering of the data, an accuracy of approximately ±18 years is found at a confidence interval of 75%, which is, unfortunately, of limited practical interest. We found new sex differences of bone density decay in the skull that are potentially of relevance for the general understanding of bone degradation processes.