An Investigation of Hyperostosis Frontalis Interna in a Modern Anatomical Body Donor Population

This research sought to examine the prevalence and severity of hyperostosis frontalis interna (HFI) in the Chicagoland anatomical body donor population. The study further aimed to elucidate potential demographic risk factors for HFI, including sex, age at death, and structural vulnerability index (SVI), as well as any common comorbidities, as gleaned from death certificates. HFI is an irregular bony overgrowth of the endocranial surface of the frontal bone. It is most often observed in postmenopausal women or in individuals with growth hormone disorders. This work investigated the distribution of HFI in a predominantly geriatric anatomical body donor population (n_total = 235, n_female = 127 n_male = 108; 19-104 years), using a macroscopic classification system that considers both the morphological appearance and the size of the affected area. Relationships between HFI and variables of interest were assessed through various non-parametric statistical tests and binomial logistic regression. While HFI was not associated with age-at-death or SVI, results indicate that there were significant sex differences in both HFI prevalence and severity. Females demonstrated higher rates of HFI across all severity types, whereas in males, HFI lesions were much less common and mostly limited to the earliest stages of disease progression. HFI was also associated with neoplasms as a cause of death. Among cancer deaths, individuals with hormone-sensitive cancers had a higher prevalence of HFI, but this difference was not statistically significant. While the causal pathways of these relationships remain unclear, the association with cancer may potentially explain the reportedly higher HFI prevalence rates in modern compared to past populations. Moreover, this research has bioarcheological and forensic implications as HFI is sometimes used to infer age and sex, given its association with older-aged females.