Tri-dimensional pattern analysis of foodstuff bitemarks: A quantitative method of comparison

Bitemark analysis has long been an important field within of forensic odontology, yet it remains controversial due to its inherent subjectivity and the limitations of currently adopted 2D methodologies. The National Institute of Standards and Technology has highlighted the lack of sufficient scientific foundation for conventional bitemark analysis, particularly with respect to bitemarks impressed on human skin, concerning uniqueness, reproducibility, and evidentiary reliability. Rather than addressing the limitations identified for human skin bitemark analysis, this study proposes a three-dimensional quantitative protocol specifically designed for the analysis of bitemarks impressed on a standardized food substrate. Bitemarks were imprinted on standardized Italian cheese (scamorza) by eight adult volunteers. Dental casts and corresponding food items were digitized using a REVOPOINT Blue Light Mini 3D scanner. Digital models were processed with GOM Inspect and analyzed through: surface superimposition with colorimetric deviation mapping, extraction of 2D profiles from 3D data, and computation of three quantitative indicators: three-point angle, distance-perpendicular ratio, and elliptical ratio. A probabilistic model evaluated the likelihood of a match between each bitemark and dental arch. The 3D workflow minimized evidence handling and preserved bite pattern integrity. Colorimetric maps highlighted deviations within 5 mm and 2 mm tolerance ranges, enabling screening and refined matching. Quantitative indicators showed good discriminatory power, with correct matches for all subjects except one. Substrate deformation cases emphasized integrating surface analysis with profile-based indicators to reduce geometric distortion. The combined use of 3D scanning and reverse engineering reduced angular distortion and information loss typical of 2D methods, yielding more consistent and reproducible results within the experimental conditions adopted in this study. This study demonstrates a standardized engineering-based workflow for the quantitative analysis of bitemarks impressed on a stable food substrate. The proposed protocol provides objective and reproducible quantitative parameters for this specific experimental scenario and should not be interpreted as validation or direct support for bitemark analysis performed on human skin, whose biomechanical characteristics and distortion mechanisms differ substantially from those of stable inanimate substrates.