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The Relationship Between Localized Bone Density and the Area and Perimeter of Exit Wounds

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This study tested the relationship between the size of cranial gunshot exit wounds and localized bone density (i.e., bone density directly adjacent to an exit wound).
Bone density data has the potential to be a valuable tool in ballistic trauma analysis due to its effect on size and shape of entrance and exit wounds. Bone density is often measured via DEXA scans, but can also be measured from CT scans. Thirty-seven donated human heads sourced from an anatomical tissue supply company were subjected to gunshot trauma as part of a larger project. Prior to shooting, each head was placed on a shooting stand at approximately adult male height. Each head was then shot once with a 0.38 revolver either through the frontal or temporal/parietal bone. Bullets were either full metal jacket or jacketed hollow points. Following the experiment, heads were CT scanned, autopsied, and processed using standard maceration techniques. Bone density measurements were collected from the CT scans (using Mimics 20.0) in an area of bone measuring 31-33 mm2 located immediately superior to the exit wounds. Area and perimeter measurements of exit wounds were collected using ImageJ. All data were then subjected to Pearson product moment correlation tests. Preliminary results revealed a medium strength correlation (.510) between bone density and exit wound perimeter. These results indicate that bone density likely has a significant effect on the size of gunshot exit wounds, and this has implications for interpreting such wounds. (publisher abstract modified)

Date Published: January 1, 2019