Estimation of sex from index and ring finger in a North Indian population

Gender determination in adults using calcaneal diameters from lateral foot X-ray images in the Iranian population

Background: Using morphologic features of the bones is the basis of gender determination in anthropology and forensic medicine. In this study, we evaluated the calcaneus diameters for gender determination in the Iranian population.

Methods: This cross-sectional study was conducted on Iranians referring to Hazrat-e Rasool Hospital’s radiology ward for plain lateral X-ray of the foot. Lateral foot X-rays from 100 men and 100 women were gathered and evaluated for calcaneal indexes. These patients aged between 18 and 80 years old who did not suffer major trauma to the calcaneus bone were recruited. Using a picture archiving and communication system (PACS), four variables were calculated for each X-ray graph: Maximum anterior-posterior length of the calcaneus (MAXL), Maximum height of the bone (MAXH), Height of the cuboid facet (CFH) and Height the calcaneal body (BH). Cut off points for each index were calculated using the area under curve (AUC) in ROC curves.

Results: Lateral foot X-rays from 100 men and 100 women were gathered and evaluated for calcaneal indexes. The means of the four indexes were compared between the sexes which showed all four means are significantly different p value <0.001. AUC for MAXL in differentiating the genders was 0.824, which showed 86.8 as the cut off with a sensitivity of 80% and specificity of 69.0%. Cut off point for MAXH was set at 59.8 with sensitivity and specificity of 78.0% and 60.0%, respectively. For BH, 49.5 was set as the cut off point with a sensitivity of 79.0% and specificity of 64.0%. The best cut off point for CFH was 27.8 with 76.0% sensitivity and 63.0% specificity.

Conclusion: It can be concluded that the calcaneal diameters are reliable criteria for sex determination. Although the cutoff points are different between various races and populations, it is evident that these diameters can be used for sex determination in general.

Different predictive and accuracy models for sex and stature estimation from second- and fourth-digit lengths in the Kinnaur population of Himachal Pradesh, North India: Medico-legal and forensic implications

Forensic anthropologists are not only active in courtroom testimonies but also contribute to disaster victim identification. The timely recovery and identification of victims in any disaster is crucial, and anthropologists play a vital role in this process. In mass disasters such as airplane crashes, tsunamis, earthquakes or terrorist attacks, fragments of dead bodies are usually brought for identification. Each fragment demands special tactics to fulfil any of the basic attributes of forensic identification such as age, sex, stature or ancestry. If sex and stature can be estimated from a single fragment, then it can potentially reduce the identification time and possible victim matches. In this study, an attempt has been made to estimate sex and stature from the second- and fourth-digit lengths. Different predictive and accuracy models have been devised using statistical techniques. No bilateral difference was observed in the digit lengths in either sex. Consequently, an average of the digit lengths was employed for model approximations. The fourth-digit length provided the best sex estimates (M=82.1%, F=79.2%) when binary logistic regression (BLR) statistics were applied. It was also observed that overall sex estimations improved from 78.8% (from BLR) to 79.8% when discriminant function analysis was used for sex estimation. Second- and fourth-digit lengths were used independently and together for stature estimation models for males and females individually and for the pooled sample. In stature estimation models, three major interpretations were perceived: (1) the second-digit length provided the best stature estimates; (2) the estimation models compute better stature estimates for females than their counterparts, that is, standard errors are less in females than males; and (3) second and fourth digits predict more reliable stature estimation when the sex of the digits is known than that of the pooled sample.

Stature estimation from different combinations of foot measurements using linear and multiple regression analysis in a North Indian male population

Establishing the identity of the deceased is the most important task for forensic anthropologists in forensic case-work involving unidentified human remains. In such cases, forensic anthropologists examine the remains to derive the biological profile of the deceased i.e. estimation of age, sex, stature, and ethnicity to narrow down the search of the missing. Dismembered remains are recovered in mass disasters such as train mishaps, airplane crashes, earthquakes, and terrorists' attacks or in homicidal cases where perpetrator intentionally mutilates the dead body to conceal the identity of the victim. Stature estimation is considered as one of the most important tasks when a mutilated foot is recovered in process of narrowing down the pool of possible suspects/victims. Allometry is the underlying principle for estimation of stature from foot dimensions. It has been learnt from the published literature that multiple regression models including more than one factor enhances the estimation accuracies. Among the various foot dimensions, foot length is the most frequent parameter used in the estimation of stature in forensic literature. In the present study, an attempt has been made to standardize the stature estimation models from various possible combinations of foot dimensions. For this purpose, 388 Jatt Sikh males aged between 18 and 30 years were recruited from various villages of Ludhiana district of Punjab State in Northern India. Stature, five foot length measurements, and two foot breadth measurements were taken on each subject. Linear and multiple regression models were derived for the estimation of stature from various foot measurements. The highest coefficient of determination and estimation accuracy (the least standard error of estimation S.E.E) was observed from T1 (R² = 0.397, S.E.E = 4.7109) when a single foot dimension was included in the model, (R² = 0.416, S.E.E = 4.6425) from (T1, T3) when two-foot lengths were taken, (R² = 0.418, S.E.E = 4.6426) from (T1, T3, T4) when three-foot lengths were included, (R² = 0.418, S.E.E = 4.6473) from (T1, T3, T4, T5) when four-foot lengths were included, and (R² = 0.418, S.E.E = 4.6531) when all the five foot lengths (T1, T2, T3, T4, T5) were included in the regression model. It has been concluded that multiple regression models provide more accurate results than linear regression models. However, inclusion of a factor having a weak correlation with stature in the regression model, decreases the accuracy of the model.

The development and status of forensic anthropology in India: A review of the literature and future directions

Forensic anthropology deals with the identification of human remains in a legal setting. The primary role of a forensic anthropologist is to evaluate human skeletal remains and ascertain the biological profile of the deceased. Forensic anthropologists thus use their expertise to assist medical examiners, as well as law enforcement agencies. Forensic anthropology was not recognised as a subject specialty of much significance in most parts of the world for a long time. However, now its status has changed, mostly in the USA and parts of Europe. The scope of the subject ranges from evaluation of human skeletal remains to the identification of the living. In the new millennium, the role of forensic anthropologists includes disaster victim identification, photographic superimposition, facial image reconstruction in CCTV footage, gait pattern analysis from video surveillance, ascertaining the age of an individual in absence of legal documents and paedo-pornographic materials. Despite its relevance in human identification, the development of forensic anthropology in India is not very encouraging. Only a few institutions in India include forensic anthropology as a part of the forensic science degree programme, and there are no certified courses in anthropology either. Likewise, there are limited employment opportunities for forensic anthropologists in medical institutes/organisations/universities. This comprehensive review focuses on the status and development of forensic anthropology in India and emphasises the need for its recognition as a specialty of significance. The article also throws light on the comparison of its status in the Indian context vis a vis developed nations.

Estimation of Sex From Index and Ring Finger Lengths in An Indigenous Population of Eastern India

INTRODUCTION

Forensic anthropology involves the identification of human remains for medico-legal purposes. Estimation of sex is an essential element of medico-legal investigations when identification of unknown dismembered remains is involved.

AIM

The present study was conducted with an aim to estimate sex from index and ring finger lengths of adult individuals belonging to an indigenous population of eastern India.

MATERIALS AND METHODS

A total of 500 unrelated adult individuals (18-60 years) from the Rajbanshi population (males: 250, females: 250) took part in the study. A total of 400 (males: 200, 200 female) participants were randomly used to develop sex estimation models using Binary Logistic Regression Analysis (BLR). A separate group of 200 adults (18-60 years) from the Karbi tribal population (males 100, females 100) were included to validate the results obtained on the Rajbanshi population. The univarate and bivariate models derived on the study group (n=400) were tested on hold-out sample of Rajbanshi participants (n=100) and the other test population of the Karbi (n=200) participants.

RESULTS

The results indicate that Index Finger Length (IFL) and Ring Finger Length (RFL) of both hands were significantly longer in males as compared to females. The ring finger was longer than the index finger in both sexes. The study successfully highlights the existence of sex differences in IFL and RFL (p<0.05). No sex differences were however, observed for the index and ring finger ratio. The predictive accuracy of IFL and RFL in sex estimation ranged between 70%-75% (in the hold out sample from the Rajbanshi population) and 60-66% (in the test sample from the Karbi population). A Receiver Operating Curve (ROC) analysis was performed to test the predictive accuracy after predicting the probability of IFL and RFL in sex estimation. The predicted probabilities using ROC analysis were observed to be higher on the left side and in multivariate analysis.

CONCLUSION

The study concludes that sex estimation from index and ring finger lengths could be of utility when more reliable means of sex estimation are not available during medico-legal investigations.

Determination of sex from various hand dimensions of Koreans

In the case of disasters or crime scenes, forensic anthropometric methods have been utilized as a reliable way to quickly confirm the identification of victims using only a few parts of the body. A total of 321 measurement data (from 167 males and 154 females) were analyzed to investigate the suitability of detailed hand dimensions as discriminators of sex. A total of 29 variables including length, breadth, thickness, and circumference of fingers, palm, and wrist were measured. The obtained data were analyzed using descriptive statistics and t-test. The accuracy of sex indication from the hand dimensions data was found using discriminant analysis. The age effect and interaction effect according to age and sex on hand dimensions were analyzed by ANOVA. The prediction accuracy on a wide age range was also compared. According to the results, the maximum hand circumference showed the highest accuracy of 88.6% for predicting sex for males and 89.6% for females. Although the breadth, circumference, and thickness of hand parts generally showed higher accuracy than the lengths of hand parts in predicting the sex of the participant, the breadth and circumference of some finger joints showed a significant difference according to age and gender. Thus, the dimensions of hand parts which are not affected by age or gender, such as hand length, palm length, hand breadth, and maximum hand thickness, are recommended to be used first in sex determination for a wide age range group. The results suggest that the detailed hand dimensions can also be used to identify sex for better accuracy; however, the aging effects need to be considered in estimating aged suspects.

Sex determination in highly fragmented human DNA by high-resolution melting (HRM) analysis

Sex identification in ancient human remains is a common problem especially if the skeletons are sub-adult, incomplete or damaged. In this paper we propose a new method to identify sex, based on real-time PCR amplification of small fragments (61 and 64 bp) of the third exon within the amelogenin gene covering a 3-bp deletion on the AMELX-allele, followed by a High Resolution Melting analysis (HRM). HRM is based on the melting curves of amplified fragments. The amelogenin gene is located on both chromosomes X and Y, showing dimorphism in length. This molecular tool is rapid, sensitive and reduces the risk of contamination from exogenous genetic material when used for ancient DNA studies. The accuracy of the new method described here has been corroborated by using control samples of known sex and by contrasting our results with those obtained with other methods. Our method has proven to be useful even in heavily degraded samples, where other previously published methods failed. Stochastic problems such as the random allele drop-out phenomenon are expected to occur in a less severe form, due to the smaller fragment size to be amplified. Thus, their negative effect could be easier to overcome by a proper experimental design.