Human identification through smile photographs: Comparison of two methods based on selfies

This study aimed to compare the accuracy of two human identification methods based on selfies. The maxillary teeth of five adults were three-dimensionally acquired via intraoral scanning—being the simulated postmortem (PM) records. To simulate antemortem (AM) records, the five individuals took selfies of their smile. For each participant, five additional volunteers with similar ages and population affinities were requested to take selfies, which were used as foil AM records. Then, five sets containing the intraoral scan image, the respective selfie, and five foil selfies were assembled and sent to 29 forensic odontologists. The experts applied two analytical methods: the smile line and dental superimposition. The experts initially excluded the foil selfies and then identified the correct PM and AM match. Both methods allowed the same number of correct (n = 123) and incorrect (n = 22) exclusions of foils (p > 0.05). The smile line and the dental superimposition methods resulted in 94 and 86 correct, as well as 51 and 59 incorrect matches (p > 0.05), respectively. These methods must be cautiously considered and combined with other methods for safer forensic practices.