Louisiana Research Day Program Book 2025

Anatomy and Epidemiology

Anatomy and Epidemiology

Jenna Dittmar, PhD; Bailey Lenamond, OMS-II VCOM-Louisiana 41 SEXUAL DIMORPHISM OF THE HUMAN FEMUR

Cara Hanks, OMS-II 1 ; Marci Peck, OMS-II 1 ; Kenny-Khai Vo, OMS-II 1 ; Grace Pick, OMS-II 1 ; Jenna M. Dittmar, PhD 1 1 VCOM-Louisiana 42 IN SEARCH FOR A NEW GOLDEN RATIO: A COMPARISON OF THE FORAMEN MAGNUM AND THE SKULL

Background: Sexual dimorphism in the human skeleton has long been recognized, and numerous methods that assess the sexually dimorphic characteristics of the pelvis and skull are routinely used by forensic specialists and biological anthropologists to create biological profiles of human skeletons. In cases where these elements are not preserved, metric approaches are often used to estimate the biological sex of unknown individuals from prehistoric, historic and modern populations. As much previous research has demonstrated that metric sexing methods are population specific it remains necessary to continue to develop methods specifically for the populations that these methods will be used on. The aim of this research is to explore if the the maximum length of the femur can be used to determine the biological sex in modern populations. An osteometric board was used to acquire the maximum length of the femora from 25 formalin embalmed cadavers of known age and sex from the West South-Central States of the United States of America. We found that using an averaged sectioning point with the data gave us an accuracy of 77.78% on the left femur and 81.82% on the right femur. This shows that

maximum femur length can be used to estimate biological sex in modern populations from this region. Further research will explore the potential of other osteometrics to estimate biological sex in modern populations.

Context: The foramen magnum is an important structure in the skull that has implications for use both clinically and archaeologically. In their work A golden ratio for foramen magnum: an anatomical pilot study Ulcay et. al. (2021) created an experimental design that concluded there is a consistent ratio between the width and length of the foramen magnum and the skull that allows for measurement of the skull to predict foramen magnum measurements. Objective/Hypothesis: This study aims to determine if the ratio found by Ulcay et. al (2021) holds true when applied to a set of modern calvaria. Materials and Methods: The anteroposterior and transverse diameter of the foramen magnum of twenty formalin embalmed cadavers (M=8, F=12) were measured using digital sliding calipers. The length and width of each calvaria was measured using an osteometric board. Indices comparing the widths and the lengths of the foramen magnum and the calvaria were calculated, as well as a ratio to see if one measurement could be used to predict the other.

Results: Comparison of the two indices showed that they were somewhat similar (1.36). The average coefficient for cranial width to foramen magnum width was 5.08 ± 0.73, while the average coefficient for cranial length to foramen magnum length was 6.85 ± 1.70. The average between these coefficients was 5.96 ± 1.25. However, when trying to use this coefficient to predict other measurements of the skulls, the ratio could not give an accurate prediction. Conclusions: On this set of cadavers, the foramen magnum and cranium did not seem to have a consistent ratio from skull to skull. The average coefficient was much different than the golden ratio found by Ulcay et al., (2021). This could be due to the presence of remnant soft tissues instead of clean skulls. More research needs to be done on a larger set of bodies.

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2025 Research Recognition Day