Differentiating 3D-printed deceptive bite marks from natural dentition: a digital analysis approach

This study aimed to assess the detectability of bite marks created by three-dimensional (3D)-printed deceptive splints compared to those created by natural dentition using a high-precision digital workflow involving intraoral scanners (IOS) and 3D deviation analysis. Maxillary digital impressions were obtained from 16 volunteer participants to fabricate deceptive splints using a 3D printer, replicating a target individual’s dental anatomy. Bites were registered on three substrates with varying rheological properties: chewing gum, soft candy, and chocolate. Bite marks were generated using both natural dentition and deceptive splints. Samples were digitized using an IOS, and datasets were superimposed using reverse engineering software. Differences in root mean square (RMS) deviation values were statistically analyzed (α = 0.05). Method validation confirmed high precision for the scanner (3.90 μm) and the 3D printer (4.40 μm). The natural and deceptive bite marks demonstrated significant differences across all substrates ( P ≤ .005). The deceptive group consistently exhibited significantly higher RMS deviation values than the intra-subject repetition of natural bites. Chewing gum provided the highest discriminative resolution ( P < .001), whereas chocolate showed higher material variability but remained statistically distinguishable. Although desktop 3D-printing technology enables high-fidelity dental structure replication, bite marks from rigid resin splints are distinguishable from natural dentition through high-precision digital superimposition analysis. The proposed digital workflow offers a reliable method for detecting fabricated bite marks, reinforcing the utility of IOS in forensic odontology.