Forensic Anthropology Unit, Office of Chief Medical Examiner-New York City
Friday 8:00-8:15, Parlors
Distinguishing human from nonhuman bone fragments is usually accomplished by observation of gross morphology. When macroscopic analysis is insufficient, histological approaches can be applied. Certain microscopic traits, such as the presence of plexiform bone or osteon banding, are characteristic of nonhuman bone. In the absence of such features, however, distinguishing Haversian bone as either human or nonhuman proves problematic. This study proposes a histomorphometric approach for classifying human from nonhuman samples using Haversian bone.
Two variables, osteon area (On.Ar.) and circularity (On.Cr.), are examined. Measurements were collected from a sample of three species (deer, dog, human) represented by various skeletal elements (ribs, humeri, femora). ANOVAs and discriminant function analysis (DFA) were used to analyze data. Results demonstrated no significant difference across long bone anatomical quadrants and only minor variation in On.Cr. within the nonhuman sample across elements. DFA run on the variable means for each sample demonstrated clear overlap in deer and dog samples, clustering the nonhuman and human groups apart from each other. Mean On.Cr. proved a poor criterion, while mean On.Ar. proved useful in identifying human from nonhuman samples. When both variables were combined, accuracy increased to 100% correct classification for data from the ribs only and 98.4% when considering all elements. Similar results were obtained when DFA was run on individual osteon measurements. This indicates that the measurements of On.Ar. and On.Cr. are valuable histomorphometric tools for distinguishing human from nonhuman Haversian bone, even when the skeletal element is unknown and the number of measurable osteons limited.