This article examines how slight variations in radiographic orientation affect sinus outlines and how they can potentially impact postmortem identification.
The utility of frontal sinuses for personal identification is widely recognized, but potential factors affecting its reliability remain uncertain. Deviations in cranial position between antemortem and postmortem radiographs may affect sinus appearance. The research discussed in this article investigated how slight deviations in orientations affect sinus size and outline shape and potentially impact identification. Frontal sinus models were created from CT scans of 21 individuals and digitally oriented to represent three clinically relevant radiographic views. From each standard view, model orientations were deviated at five-degree intervals in horizontal, vertical, and diagonal (e.g., left-up) directions, totaling 27 orientations per individual. For each orientation, sinus dimensions were obtained, and outline shape was assessed by elliptical Fourier analyses and principal component (PC) analyses. Wilcoxon sign rank tests indicated that sinus breadth remained relatively stable, while sinus height was significantly affected with vertical deviations. Mann-Whitney U tests on Euclidean distances from the PC scores indicated consistently lower intra- versus inter-individual distances. Two of the three orientations maintained perfect (100 percent) outline identification matches, while the third had a 98 percent match rate. Smaller and/or discontinuous sinuses were most problematic, and although match rates are high, practitioners should be aware of possible alterations in sinus variables when conducting frontal sinus identifications. (Publisher Abstract Provided)