UBC Theses and Dissertations
A comparative reliability analysis of computer-generated bitemark overlays McNamee, Anne H.
Bitemark evidence is routinely accepted in the judicial system, but with recent United States court rulings such as Daubert and Kubmo an emphasis has been placed on establishing the validity and reliability of current scientific techniques. The current study compares the reliability of two popular methods used to produce computer-generated bitemark overlays. Images of twelve dental casts were sent to thirty examiners. Examiners were instructed to produce an overlay for each cast image based on the instructions provided for the two techniques. After the overlays were submitted, measurements of the area of the biting edge and the x-y coordinate of each tooth's position were obtained. The reliability assessment of the measurements was performed using an analysis of variance and calculation of reliability coefficients. The analysis of variance results showed that the forensic experience level of the examiner and the cast variations all contribute to a significant effect in the variances seen for the area for both techniques. The inter- and mtira-examiner reliability coefficients are low. The results for the positional measurements showed the forensic experience level of the examiner contributes no significant differences to the variances. The differences are seen within the cast variations. The inter- and intra-examiner reliability coefficients are exceptionally high. It was concluded that both techniques were reliable methods to produce bitemark overlays to assess tooth position.
Item Citations and Data