CT scan images for sex discrimination – a preliminary study on Gujarati population Mitalee Mehta a , Vineeta Saini b , Surinder Nath c , Shobhana Karuveetil Menon a,n a Department of Forensic Science, Gujarat University, Ahmedabad, Gujarat, India b Department of Forensic Medicine, Institute of Medical Sciences, BHU, Varanasi, India c Department of Anthropology, Delhi University, Delhi, India article info Article history: Received 24 April 2014 Received in revised form 12 October 2014 Accepted 23 November 2014 Available online 3 December 2014 Keywords: CT scan Sex estimation Discriminant function Cranio-facial parameters Gujarati population abstract Objectives: Sex estimation of skeletal remains can lead the forensic anthropologist to the identification of the remains. Skull is one of the most encountered skeletal remains. Different craniofacial parameters have differing capacities to estimate the sex. Materials and methods: In present study, volume rendered CT scan images of 143 adult living patients (66 female and 77 male) were studied. The criteria for inclusion were Gujarati origin and patients without fracture of the skull. The cranio-facial parameters studied were maximum frontal breadth, minimum frontal breadth, maximum cranial length, morphological facial height, nasion–prosthion length, bizygo- matic breadth and bimaxillary breadth. Results: Accuracy of sex estimation ranges from 61.3% to 88.7%, making the maximum cranial length and bizygomatic breadth best individual parameters with accuracy of 78.2%. The highest accuracy of 88.7% was obtained with combination of maximum cranial length, bimaxillary breadth and morphological facial height. Conclusion: Discriminant function for identification of sex was obtained with satisfactory accuracy rates for the parameters under study. It indicates that the skulls of Gujarati population are dimorphic enough to identify the sex of unknown skulls obtained from crime scene. & 2014 Elsevier Ltd. All rights reserved. 1. Introduction In recent years role of forensic anthropologists in crime investigation as well as in other kinds of investigations has been increased tremendously. An anthropologist assists the identifica- tion of human remains by creating a biological profile through the analysis of sex, ancestry, age, and stature. Sex estimation of these skeletal remains is one of the key functions of the forensic anthropologist as it lowers down the number of probable victims to the half. The accuracy of the sex estimation from skeletal remains varies according to bones and their fragmentary condi- tion, intrinsic variability in the studied population and choice of method. The maximum accuracy of sex estimation is obtained when the whole skeleton is available for the purpose [1]. Several metric studies have claimed to obtain better classification accura- cies using different parts of skeleton [2–11]. Study of morpholo- gical features of the skull includes determination of the presence or absence and the extent of the development of different features in both the sexes [12–14]. Sex can be determined with the accuracy level of more than 80% when morphological traits are studied [13]. But basic need for morphological examination is the judgement capacity and expertise of the examiner which makes the scope of method very limited. The alternate and more reliable approach is the metrical one which uses different linear and angular measurements of the skull, which are totally based on the pre-defined landmarks. Different parts of the skulls are used for measurements and the accuracy levels for sex estimation also vary with the part of the skull involved in the study [15–43,45–47]. Further, some populations are considered to be much dimorphic, e.g. African black. The types of the samples used for different anthropological studies, conducted to estimate the sex, also vary. Generally, the dried skulls from the collection of particular origin are used as samples for the study which do have all the details regarding their identification like sex, age, stature and origin. Use of skulls, freshly extracted from dead bodies is also an alternate to these kinds of collections. Here, the pre-treatment is required to remove the flesh adhered to the subjected bone [48]. In the case of unavailability of any type of skulls with the required data, different radiographic techniques can be used. [37]. The cephalograms have been widely used in the field of forensic anthropology, including in the sex Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/jofri Journal of Forensic Radiology and Imaging http://dx.doi.org/10.1016/j.jofri.2014.11.009 2212-4780/& 2014 Elsevier Ltd. All rights reserved. n Correspondence to: Department of Forensic Science, University School of Sciences, Gujarat University, Navarangpura, Ahmedabad 380009, Gujarat, India. Tel.: þ91 79 26300435. E-mail address: shobhanamenon07@gmail.com (S.K. Menon). Journal of Forensic Radiology and Imaging 3 (2015) 43–48