Morphometric analysis of the frontal sinus: application of industrial digital radiography and virtual endocast

Abstract

Abstract Background The morphology and dimensions of the frontal sinus (FS) are significant in the forensic, surgical and population context. Purpose The study aimed to compare linear FS measurements taken both on radiographs and virtual endocasts and to assess the impact of the skull angulation on the FS dimensions. Material and Methods Thirteen intact dry skulls of contemporary adult males were radiographed using industrial digital radiography while they were inclined in the Frankfurt plane, through the Caldwell's view up to the Water's view by angular steps of 5°. The width and height of both frontal lobes were measured in each projection. To verify the measurements on the radiographs, ten of the skulls were µCT-scanned and virtual endocasts of the FS were generated. Results The concordance between the measurements on the virtual endocasts and the radiographs in the Caldwell's view showed almost perfect concurrence for the width (0.998) and height on the left side (0.990), and substantial one for the height on the right side (0.961). Since the width is more sensitive compared to the height, any inclination from the initial position at the Caldwell's view caused a significant distortion of the FS measurements. Conclusion The industrial µCT-systems support both 2D and 3D imaging and could generate images with a high resolution. Therefore, if the industrial digital radiography is selected as an eligible imaging modality for FS investigation and documentation in conformity with the research goals, the appropriate skull positioning ensures reliable readings of the linear FS dimensions.