Value of histological study in the fronto-sphenoidal suture for the age estimation at the time of death

The macroscopic study of cranial sutures is one of the methods that may be used in forensic anthropology to estimate age at the time of death. The present study aims at assessing the value of a microscopic analysis of the fronto-sphenoidal suture (FSS) sampled at autopsy, to determine both the physiological mechanisms responsible for the FFS closing during ageing and its value in the estimation of age at the time of death. We assessed the vascular capital as well as the apoptosis of conjunctive cells intervening as parameters in the physiological mechanism involved in cell ageing, in a population of individuals, whose gender and age was known. The FSS analysis was performed after decalcification and standard histological study, respectively with immunohistochemistry (Factor Von Willebrand antibody) VWF and (TdT-mediated dUTP nick end labelling) TUNEL method and caspase-3 immunohistochemical expression. In this study we found a significant reversed correlation between the degree of vascular expression of VWF and age at the time of death. There was also a significant positive correlation between the degree of apoptosis in the conjunctive cells of the FSS and age at the time of death. According to these results, suture closing during ageing can be explained by these two combined mechanisms of conjunctival apoptosis and vascular involution. Thus, the findings justify the study of closing sutures to estimate age at the time of death. Besides, it also enabled us to establish linear regressions. The vascular expression of the VWF enables to estimate an individual's age at the time of his death more or less at about 1.55 years, offering an interesting perspective both in forensic pathology and anthropology.