Neurocranial Histomorphometrics

Successful development of the biological profile employs a variety of traditional methods. A key disadvantage is the necessity of near complete and proper preservation of target elements to reliably estimate age and sex. Instances lacking traditional gross odonto-skeletal features force anthropologists to rely on bone or dental microscopy.

The majority of relevant histological research has focused primarily on the long bones and estimating age-at-death. One limitation is the insufficient attention to how biomechanical and metabolic factors affect the osteonal remodeling process in long bones and the accuracy of aging techniques. The influence of variation resulting from localized trauma, as well as the generalized effect of diet, disease, or excessive or minimal physical activity, is also important.

Studies have also discussed microstructural differences between the sexes. There is a discord in the research as to whether or not males and females should be considered separately in establishing age-at-death estimations. However, there is no evidence in the literature as to the value of using histomorphometrics to estimate sex itself.

This research examines the neurocranium. Forty-eight white male and female decedents of known age and sex from the University of Tennessee Knoxville Medical Center were sampled during autopsy to remove specimens from the sectioned calotte of the left frontal, parietal and temporal bones for thin-section analysis.

A research light microscope and computer imaging software were used to examine slides at various magnifications; photographic series of the entirety of each thin-section was captured using a mounted digital camera attachment. Twelve sub-variables were measured. Statistical analyses found no significant differences in mean sub-variable measurements between the internal and external tables of the thin-sections. Significant differences were noted between the sexes and by bone. Therefore, sub-variable correlations with age and regression equations to estimate age-at-death were created both together and separately for males and females for each neurocranial bone.

A discriminant function analysis assessed if the histomorphometrics could estimate sex. This test proved to be 80% accurate at classifying females and 90% accurate at classifying males when considering all three bones in the analysis.