Hyperostosis frontalis interna as an age-related phenomenon – Differences between males and females and possible use in identification

Abstract

Hyperostosis frontalis interna (HFI) is a condition manifested by thickening of the inner surface of the frontal bone and it could be useful when dealing with the identification of human remains in various anthropological and forensic investigations. We compared the macroscopic appearance and morphologic (metric) features of the skulls in cases with and without HFI, in both sexes, and wanted to establish whether age determined occurrence of HFI. To achieve this aim, we performed prospective autopsy study, covering ten-year period (2007–2016). Study group consisted of southeast Europe Caucasian subjects, with determined age and sex. The severity of HFI was classified by two forensic pathologists independently, according to the four types (A–D) proposed by Hershkovitz et al. Thicknesses of the frontal and temporal bones, as well as the longitudinal and frontal diameters of the skulls were measured. The sample consisted of 35 males and 112 females with HFI, and 55 males and 202 females without HFI (404 individuals in total). Type B was the most common type of HFI among males (45%) and type C among females (41%). HFI type D was almost four times more common in females than in males (OR = 3.73). Frontal and temporal bones were thicker in all subjects who have HFI. Thickness of the skull was not age-dependent, in the entire sample, or in subjects with HFI, or in the control group (in all the cases Spearman's Rho was <0.3). Age seemed to be a predicting factor for HFI occurrence only in females. Females younger than 55 years have similar risk for HFI occurrence as males. An unidentified skull with the general markers of old age and severe form HFI is most probably from a female decedent.