SHORT COMMUNICATION Evaluating the morphological and metric sex of human crania using 3-dimensional (3D) technology Victoria Berezowski 1 & Tracy Rogers 1 & Eugene Liscio 1 Received: 5 December 2019 /Accepted: 16 April 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Identifying the skeletal remains of an unidentified individual is a priority for the medico-legal system because identification increases the chances of finding the person responsible and provides closure to the family. The purpose of this research was to develop a combined morphological and metric cranial sex assessment method using 3D technology that accommodates the medico-legal system, and their use of 3D models facilitates the technological transition to digitally archived skeletal collections. A total of 91 individuals of European biogeographical ancestry from the William M. Bass Donated Skeletal Collection (University of Tennessee Knoxville) were imaged using photogrammetry, turned into 3D models using Agisoft PhotoScan, and digitally evaluated using 3D Studio Max. This novel method digitally evaluated five cranial traits, including the nasal aperture height, nasal aperture width, mastoid length, the general size and architecture, and the supraorbital ridges, combining techniques that can only be done digitally with those that can be completed on the actual bone. Preliminary statistical tests demonstrate an overall accuracy rate of 90% when tested against the training sample (20 males, 20 females) and 75% when tested against the test sample (51 individuals). Although no intra- or inter-observer error rate tests were done, and further testing on other skeletal collections is necessary, this method allows forensic anthropologists to perform relatively easy point-to-point measure- ments, the quantification of traditionally non-quantified traits, the possibility of reproducible results, and the ability for future analyses or research. Keywords Forensic science . Forensic anthropology . Sex assessment . 3D technology . Crania . Photogrammetry . Digital documentation Introduction When faced with unidentified human remains, forensic an- thropologists construct a biological profile which includes the sex, age, and ancestry of the individual [1]. This informa- tion is then given to the police to narrow down the list of missing persons [1]. Creating an accurate biological profile is vital in a medico-legal context because identification increases the chances of finding the person responsible and provides closure to the family [1]. Of the three aspects of the biological profile, research has shown that the sex assessment is the most important and should be performed first because the subsequent ancestry and age analyses rely on an accurate sex assessment [2, 3]. The purpose of this research was to develop a combined morphological (shape) and metric (size) cranial sex assessment method using three-dimensional (3D) technology, to accommodate the medico-legal system and their use of 3D models and to facilitate the technological tran- sition to digitally archived skeletal collections. Some agencies in the medical and forensic science fields have made a shift to using 3D technology in order to perform virtual autopsies, improve identification methods, and analyze various types of crimes scenes and evidence [4–15]. The ap- plication of 3D techniques, specifically to anthropological methods, has shown marked benefits both during analysis and in court. First and foremost, creating a 3D model elimi- nates the handling and fragility concerns associated with * Victoria Berezowski Victoria.berezowski@mail.utoronto.ca Tracy Rogers tracy.rogers@utoronto.ca Eugene Liscio eugene.liscio@utoronto.ca 1 University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada International Journal of Legal Medicine https://doi.org/10.1007/s00414-020-02305-0