Contents lists available at ScienceDirect Journal of Forensic Radiology and Imaging journal homepage: www.elsevier.com/locate/jofri Part III – Adult skeletal age estimation using CT scans of cadavers: Revision of the auricular surface methods Catherine E Merritt ⁎ Centre for Anatomy and Human Identification, University of Dundee, Dundee DD1 5EH, UK ARTICLE INFO Keywords: Forensic anthropology Adult skeletal age estimation Auricular surface CT scans Volume-rendered images Lovejoy et al. method Buckberry and Chamberlain method ABSTRACT Objective: The auricular surface of the ilium is often found preserved in both archaeological and forensic con- texts. In the final manuscript of this three-part series, the features used by biological and forensic anthropologists to estimate adult skeletal age from the auricular surface are tested on volume-rendered images (VRIs) generated from CT scans of cadavers. Materials and methods: CT scans of 420 cadavers from the Victorian Institute of Forensic Medicine were selected (age range 20–79 years). Siemens syngo.via software was used to view the DICOM images and create the VRIs. The Lovejoy et al. auricular surface method of age estimation was assessed for use on VRIs and a new method for VRIs was created. Results and conclusion: Most of the features described by Lovejoy et al. could not be observed on the VRIs, and as previously established by Villa et al. (2013) [13], the Buckberry and Chamberlain method cannot be used on VRIs. Features such as transverse organization, surface texture, and microporosity are not visible on VRIs; however, features of the auricular surface and retroauricular area were seen to progress in a manner similar to that described by Lovejoy and colleagues, and a revised auricular surface method for use on VRIs was developed. The revised method is strongly correlated with age, and over 70% of the sample was placed within one standard deviation of the mean of the correct phase. This revised method should be tested on more populations using different CT settings and software. 1. Introduction The auricular surface of the ilium is often preserved in archae- ological and forensic contexts [1,2]. For this reason, methods of age estimation were developed on this region, and these methods are con- sidered to be reliable to estimate skeletal age at death [3]. The Lovejoy et al. method [1] is the most widely used auricular surface age esti- mation method [3]. Age-related changes to the fibrocartilage of the sacroiliac surface were noted in the early 20th century [4], and Lovejoy and colleagues developed their auricular surface age estimation method based on these observations [1]. Approximately 500 American–- European individuals from the Hamann–Todd Collection and 250 in- dividuals from a North American archaeological population were used to create the method, and it has been repeatedly tested on American and other populations [2,5–11] with varying degrees of success. Two major revisions to the method have been established. Buckberry and Chamberlain created a composite scoring system using five traits Lovejoy and colleagues identified as important for aging [12], and this has become a widely used method [3]. Osborne and colleagues created a revision based on the morphological features of the auricular surface, and truncated the eight-phase system to six phases [13]. While these revised methods have been tested [5,6,14–18], the Lovejoy et al. method is still the most widely used in practice [3]. Few studies have assessed the reliability of CT scan volume-ren- dered images (VRIs) on the auricular surface. Barrier et al. [19] used the Lovejoy et al. method on multi-slice CT scans of skeletal remains. They concluded that the features of surface texture, granularity, and microporosity were difficult to evaluate, even on scans of skeletal re- mains with no soft tissue, and developed a method based on transverse organization, macroporosity, apical activity, and trabecular bone quality. Similarly, Villa et al. [20] established that the Buckberry and Chamberlain method does not work using CT scan VRIs as the com- posite score relies on assessing surface texture, granularity, micro- porosity and macroporosity, and apical activity. Evaluating surface texture and granularity as described by both Lovejoy et al. and Buck- berry and Chamberlin from VRIs is difficult, and microporosity is not visible. The method developed from this study combines both auricular surface morphological features visible on VRIs and bone quality from https://doi.org/10.1016/j.jofri.2018.08.005 Received 12 January 2018; Received in revised form 11 August 2018; Accepted 13 August 2018 ⁎ Correspondence to: E-mail address: catherine.merritt@mail.utoronto.ca. Journal of Forensic Radiology and Imaging 14 (2018) 58–64 Available online 17 August 2018 2212-4780/ © 2018 Elsevier Ltd. All rights reserved. T