Estimation of Sex from Hand Dimensions in an Indigenous Karbi Adult Population of Assam, India

Personal identification is one of the most important elements in any medico-legal and forensic investigation. It is a challenging task for both the forensic experts and physical anthropologists when identifications of unknown dismembered remains are involved. The aim and objectives of the present investigation was to determine sex by using hand length (HL) and hand breadth (HB) among an indigenous adult Karbi tribe of Karbi Anglong, Assam, India. The present community based cross-sectional investigation was undertaken among 320 unrelated adult Karbi individuals (160 males;160 females) between the age-group of 20-50 years, using stratified random sampling method. The anthropometric measurements of HL and HB were collected using standard procedures. The statistical analysis of descriptive statistics, ANOVA, binary logistic regression (BLR) and AUC-ROC were performed using SPSS (version 16.0). The results indicate that mean of LHL, RHL, LHB, RHB, LHI and RHI were observed to be significantly higher among men than women (p<0.01). The investigation highlights the existence of sexual dimorphism in HL and HB (p<0.01). The mean bilateral difference was found to be statistically not significant in both sexes in HL and HB (p>0.05). The BLR analysis showed that HB was found to be significantly more associated with sex estimation than the HL in both sexes (p<0.01). The AUC-ROC analysis was performed to test the predictive accuracy in sex estimation after predicting the probability of HL and HB. The AUC-ROC analysis showed that combined HB than HL have more accuracy over a single hand dimension measure (for example, LHL, RHL, LBH and RHB) to determine the sex (p<0.01). The equation of the present investigation may prove to be useful in sex estimation of an adult individual when any fragmented or mutilated body parts are brought for the forensic science and medico-legal investigations. Address for correspondence: Dr. Nitish Mondal, Assistant Professor, Department of Anthropology, Assam University (Diphu Campus), Diphu, Karbi Anglong 782 462, Assam, India Mobile: +91-9435508517 E-mail: nitishanth@gmail.com INTRODUCTION Personal identification is one of the most important elements in any medico-legal and forensic investigations and it is a challenging task for both the forensic scientists and forensic anthropologists. There are greater chances of finding any fragmented, mutilated and decomposed body segments from any man-made mass disasters or explosions and/or crime scenes in modern world, where the human body is partially or completely mutilated by the murderers in order to dispose off the identity of a person (Kanchan and Rastogi 2009; Kanchan et al. 2010a,b; Rongpi and Mondal 2019). The forensic experts and forensic anthropologists in such cases can give a tentative identification and estimations of unknown remains such as identification of sex, age, stature and ethnicity from the remains of the human body (Robling and Ubelaker 1997; Sen and Ghosh 2008; Jee et al. 2015; Sen et al. 2015; Kim et al. 2018; Rongpi and Mondal 2019). Sex estimation is one of the most important elements in the identification of an individual or population. It is a simple task to determine the sex when the whole body is available as the internal and external genitalia can directly suggest the sex of an individual (Asha et al. 2012; Varu et al. 2016; Caplova et al. 2017). The problem arises when the body parts found are in a fragmented or mutilated state in mass disasters, accidents, explosions and crime scenes (Agnihotri et al. 2005; Rani et al. 2011; Uhrová et al. 2015; Pal et al. 2016; Bindurani et al. 2017). Sometimes a forensic anthropologist works with skeletonised or badly decomposed body segments and collect osteometric data, which is generally straight forward in population (Sarode et al. 2009; García2 DOLOI-IM RONGPI AND NITISH MONDAL J Life Science, 12(1-2): 1-11 (2020) Parra et al. 2014; Jee et al. 2015; Curate et al. 2017; Monum et al. 2017; Ubelaker and DeGaglia 2017; Sah and Jeelani 2019). The estimation of stature or sex from various linear measurements, such as hand and foot dimensions, is the easiest components for personal identification in forensic science and medico-legal aspects (Kanchan et al. 2010a,b; Sen et al. 2011; Dey and Kapoor 2015; Jee et al. a,b 2015; Sen et al. 2015; Kim et al. 2018; Asadujjaman et al. 2019; Singh et al. 2019a). It is common to find fragmented body parts, such as hand and foot in disaster, crime scene, explosions, airplane and train accidents (Kanchan et al. 2010a,b; Jee et al. 2015; Bindurani et al. 2017; Singh and Yadav 2017; Kim et al. 2018; Zulkifly et al. 2018; Asadujjaman et al. 2019; Rongpi and Mondal 2019; Singh et al. 2019b). In such cases, estimation of the sex as well as stature from the fragmented body parts bears an utmost importance in the field of forensic science and medico-legal aspects. Several research investigations have reported sex determination using different body segments in adult individuals (Kanchan and Rastogi 2009; Sen et al. 2011; Dey and Kapoor 2015; Sen et al. 2015; Varu et al. 2015; Bindurani et al. 2017; Singh and Yadav 2017; Zulkifly et al. 2018; Asadujjaman et al. 2019). However, the number of such studies carried out in the region is so far negligible. Therefore, the needs of region/population-specific investigations are necessary owing to ethnic variations present in different regions of the world (Robling and Ubelaker 1997; Singla et al. 2012). India has an enormous number of ethnic and genetic diversity due to the composition of numbers of ethnic/indigenous elements.