This study investigates the variation between craniofacial landmarks extracted from computed tomographic (CT) scans and those collected from direct digitization of dry skulls. Thirteen traditional craniofacial landmarks were obtained from each CT scan using the coordinate option in the software Aviso. These coordinates were then compared with the coordinates digitized directly from the dry skulls as 2 separate samples and individually. Similarities were found between the 2 coordinate samples, with the first principal component representing only 23.97% of the total variation associated with the data acquisition methods, and were found to be statistically significant (P = 0.0223). Differences were more prevalent along the midline landmarks. In contrast, the individual specimen comparisons exhibited the largest amount of variation within the symmetric landmarks with the bilateral landmarks that were more medially located in the CT sample, but no individual specimens were significantly different (eg, P = 0.9883) when comparing both data acquisition modalities. The bilateral coordinates were not found to be significantly different for either analysis (P = 0.4165). The significant differences found for the entire data set suggest that the combination of CT-extracted and digitized individuals needs to be further explored with respect to the reference frames and sample composition. However, the individual specimen comparison results of this study validate the utility of CT-extracted landmarks when used for putative identifications in a forensic setting and when clinically applied.
From the Department of Sociology and Anthropology, North Carolina State University, Raleigh, North Carolina.
Received August 6, 2013.
Accepted for publication August 27, 2013.
Address correspondence and reprint requests to Amanda R. Hale, MA, NCSU, 334 1911 Building, Campus Box 8107, Raleigh, NC 27695-8107 E-mail: email@example.com
Supported by the National Institute of Justice grant no. 2005-MU-BX-K078.
The authors report no conflicts of interest.