Radiology determines identity

Evaluation of human teeth is commonly used to aid in identifying human remains. Radiographic depiction of anatomical features such as crown morphology, root characteristics and the spatial relationship between teeth can objectively identify an individual.

Robert E. Wood of the University of British Columbia in Vancouver reviewed radiographic methods that can be used to determine identity using the teeth, root structures and frontal sinuses. Radiographically assisted dental identification may be either comparative, in which radiographs from before and after death are compared to confirm identity, or reconstructive, which aids in the generation of a biological profile of a person whose identity is unknown.

One technique is digital dental radiographic identification, in which the films are digitized and a horizontal strip is cut from a radiograph exposed before or after death and placed over the corresponding area in the opposite radiograph (see figure). The degree of concordance can be assessed and subsequently provide a positive, possible or negative identification. Wood reports a device that has been developed to help re-create image geometry on films exposed after death to resolve spatial relationship issues.

Because of the anatomical complexity of facial bones, comparison radiographs of the frontal sinus may be used, as the view that demonstrates the frontal sinus provides a high-quality radiographic depiction. Several studies have been done that found radiographic sinus comparison to be a successful technique. Dental radiography also may be used for disaster victim identification in mass casualty incidents, for age determination, to demonstrate fracture patterns in blunt-force trauma of the skull or to solve claims of dental malpractice.

Wood suggests that future studies should focus on the stability of anatomical features over time, on various ethnic populations to provide reference material for age determination and on the extent to which radiographic image geometry may be used before it disallows identification. (Forensic Science International, May 15, 2006, pp. S47-S55.)