Using tibia fragments from South Africans of European descent to estimate maximum tibia length and stature

Intact long limb bones have been used in the derivation of regression equations for stature assessment in different population groups. Since intact long bones are not always present for analyses in forensic cases, it has become necessary to derive regression equations for the estimation of stature from the fragments of these bones which are obtained in forensic and archaeological cases. Regression equations have been derived for stature estimation from fragments of the tibia. Since these equations are population specific, it was the aim of this study to derive similar equations for estimation of stature and maximum tibia length from measurements of different fragments of tibia of South Africans of European descent. Analyses were based on a sample of 50 male and 50 female complete skeletons of adult South Africans of European descent. Total skeletal height for the individual skeletons was measured using the Fully's (anatomical) method. Six variables were measured on the tibia which included the medial tibial condyle lengths and breadths, lateral tibial condyle lengths and breadths, proximal breadth and distal breadth. Univariate and multivariate regression equations were formulated for estimation of total skeletal height (and subsequent estimation of living stature) and maximum tibial length from measurements of the tibia. The standard errors of estimate for the equations were higher than those obtained for intact long bones which when present in forensic cases should be used for stature estimation. In the absence of intact long bones, the equations derived from the present study can provide a reliable estimate of skeletal height and living stature.     

Quantification of the subpubic angle in South Africans

Due to the high crime rate in South Africa, forensic anthropologists are increasingly approached to aid in the identification of skeletonized remains, with sex and population affinity assignment being some of the most critical tasks they face. For over a century, the pelvis has been known to be one of the most sexually dimorphic bones of the human body and the subpubic angle is one of the most accurate, albeit scarcely quantified, features thereof. Hence, the aim of this study was to quantify the size of the subpubic angle and compare it between male and female South Africans of African (black) and European (white) descent. One hundred and forty five (145) pelves were selected, consisting of 68 white (43 male and 25 female) and 77 black South Africans (44 male and 33 female), from the Raymond A. Dart Collection of Human Skeletons housed at the University of the Witwatersrand, Johannesburg, South Africa. Each of the pelves were articulated and placed into a custom built stand for photographing. Measures of the subpubic angle from these digital images were subjected to numerous statistical analyses. Results indicated that significant differences exist between the sexes, as well as between the two population groups. For black individuals it was found that males generally possessed a subpubic angle of 74.9° or less, with larger values being indicative of the female sex. For white individuals, subpubic angles of 81.4° and less indicated males whilst larger values indicated females, with an average accuracy of 86% for both population groups. These results illustrate the advantages of using the subpubic angle to assist in the estimation of sex and population affinity and also reinforce the need for population specific parameters to be applied.     

Metric assessment of race from the pelvis in South Africans

It is well known that there are measurable differences between whites and blacks in the size and proportions of skeletal components. There are also metric differences among populations within these racial phenotypes. The population specific quantification of this variation can be used to aid in the identification of racial affinity in the absence of a more racially definitive skeletal element like the skull. Therefore, the purpose of this research is to quantify these differences in the pelvis of South African whites and blacks. A sample of 400, ostensibly healthy known sex/race os coxae was examined. Skeletal material was obtained from the Pretoria and Dart collections. A series of 13 measurements were taken Data were subjected to SPSS stepwise and direct discriminant function analysis. Pubic length was chosen as best for discriminating between races for males and iliac breadth as best in females. Highest average accuracies (Function 1) were 88% for males (pubic length, greater sciatic notch posterior width, acetabulum diameter, total height) and 85% for females (pubic length, greater sciatic notch posterior width, acetabulum diameter, iliac breath). In conclusion, this research resulted in the development of standards of identification tailored to this population and unquestionably demonstrates that race differences in the skeleton are highly significant and must be considered in all skeletal analyses.     

Stature reconstruction using fragmentary femora in South Africans of European descent

It is well documented that the intact femur has the highest correlation with stature and as such has been widely used in the derivation of regression equations for stature estimation. As intact femur is not always present for analyses in forensic cases, it has become necessary to derive regression equations for the estimation of stature from fragments of this bone. Few studies have presented regression equations for stature estimation from fragments of the femur. Because these equations are population specific, it was the aim of this study to derive similar equations for estimation of stature and maximum length of femur from measurements of the femur of South Africans of European descent. A sample of 50 male and 50 female complete skeletons were obtained from the Raymond A. Dart Collection of Human Skeletons. Total skeletal height for each of the skeletons was calculated using the Fully's method. Six variables were measured on each femur which included the vertical neck diameter, upper breadth of femur, epicondylar breadth, bicondylar breadth, lateral condyle length, and medial condyle length. Regression equations for the estimation of stature are presented. The range of standard error of estimate for these equations (3.71-5.31) was slightly higher than those obtained for intact long bones (2.13-3.79). It is therefore suggested that in the absence of intact femur, regression equations derived from the present study can provide a reliable estimate of adult stature.     

Osteometric variation in the humerus: sexual dimorphism in South Africans

There has been a surge of research on forensic anthropology in South Africa. Differences between the populations of this country and others are demonstrated in many studies. Yet, many forensic osteometric techniques based on other populations are still in use. The purpose of the present study is to develop an osteometric sex determination technique using the humerus. The sample is composed of skeletons of 104 whites and 88 blacks from the Dart and Pretoria collections. Six humeral dimensions were initially analyzed using stepwise discriminant function statistics. Humeral head diameter, deltoid tuberosity circumference and epicondylar breadth were individually calculated in order to make the technique usable for fragmented remains. The results indicated that the head and epicondylar diameters are the best in whites to differentiate sexes from each other, while head diameter and maximum length are best in blacks. Accuracy of correct classification was as high as 96% in whites and 95% in blacks. Crossvalidation provided the same accuracy as the original classification. These accuracy percentages are as high as those expected from the femur and tibia. Posterior probability, which measures the percent affiliation of the sample with its original sex group, was also mostly 80% or better. South African collections are ideal for osteometric analysis, because they are still growing in numbers with cross-sectional representatives from the country.     

Discriminant function sexing of the mandible of indigenous South Africans

South Africa currently has a high homicide rate. This results in a large number of unidentified bodies being recovered each year, many of which are referred to the forensic examiner. This situation has resulted in considerable growth of forensic anthropological research devoted to devising standards for specific application in South African medico-legal investigations. The standards suitable for Black South Africans now encompass a wide variety of skeletal elements (e.g. cranium, humerus, pelvis, femur, patella, talus, calcaneus), each with differing degrees of accuracy. Apart from a preliminary investigation of the Zulu local population, however, we note that there appears to be no established metric mandible discriminant function standards for sex determination in this population. The purpose of the present study is to undertake a comprehensive analysis of sexual dimorphism in the mandible of Black South Africans, incorporating individuals from a selection of the larger local population groupings; the primary aim is to produce a series of metrical standards for the determination of sex. The sample analyzed comprises 225 non-pathological mandibles of Black South African individuals drawn from the R.A. Dart Collection. Nine linear measurements, obtained from mathematically transformed three-dimensional landmark data, are analyzed using basic univariate statistics and discriminant function analyses. All of the measurements examined are found to be sexually dimorphic; the dimensions of the ramus and corpus lengths are most dimorphic. The sex classification accuracy of the discriminant functions ranged from 70.7 to 77.3% for the univariate method, 81.8% for the stepwise method, and 63.6 to 84% for the direct method. We conclude that the mandible is a very useful element for sex determination in this population.     

Skeletal height reconstruction from measurements of the skull in indigenous South Africans

Stature reconstruction is important as it provides a forensic anthropological estimate of the height of a person in the living state; playing a vital role in the identification of individuals from their skeletal remains. Regression formulae for stature estimation have been generated for indigenous South Africans based on measurements of long bones of upper and lower extremities and the calcaneus. Since these bones are not always available for forensic analysis, it became necessary to use other bones such as the skull for stature estimation. The aim of the present study was to investigate the usefulness of certain measurements of the skull of indigenous South Africans in the estimation of adult stature. Ninety-nine complete skeletons obtained from the Raymond A. Dart Collection, School of Anatomical Sciences of the University of the Witwatersrand, were used. Total skeletal height (TSH) was calculated for each skeleton using the Fully's (anatomical) method. Furthermore, six variables were measured on each skull. TSH was regressed onto these cranial measurements in order to obtain regression formulae. The correlation coefficients obtained ranged between 0.40 and 0.54. The range of the standard errors of estimate from the current study (4.37 and 6.24) is high in comparison to that obtained for stature estimation based on intact long bones and the calcaneus. Therefore, the equations presented in this study should be used with caution in forensic cases when only the skull is available for human identification.     

Nasal aperture shape evaluation between black and white South Africans

The purpose of this study was to combine morphoscopic and metric analyses to assess variation in nasal aperture size and shape of black and white South Africans. Thirteen landmarks were digitized from the bony nasal region of 152 crania using an electromechanic instrument for geometric morphometric (general procrustes analysis) and craniometric analyses. Elliptical Fourier analysis was used to assess shape of the nasal aperture via outlines applied through photographs. Both principal component and discriminant function analyses were applied to these statistical methods. Black South Africans were classified 95-96% correctly and white South Africans were classified 91-94% correctly. In a four-way analysis of sex and ancestry, classification accuracy ranged from 56 to 70%. Most misclassifications were between the sexes within each group which suggests an absence of sexual dimorphism. This study found that there is quantifiable variation in shape of the nasal aperture between black and white South African groups using all three statistical methods. In forensic application, standard craniometrics can be used to accurately classify an unknown person.     

Nonmetric sex determination from the distal and posterior humerus in black and white South Africans

The successful identification of human skeletal remains relies on proven diagnostic techniques for sex determination. This research utilized 608 individuals from South Africa (420 men, 188 women) to conduct a blind nonmetric determination of sex from three features of the distal humerus: olecranon fossa shape, angle of the medial epicondyle, and trochlear extension. A scoring system between males and females was implemented, and the aggregate score of the three features determined the estimated sex of the skeletal element in question. With all features combined, black and white South Africans were categorized successfully as either male or female 75.5% (77% accuracy rate for females, 74% accuracy rate for males). This classification rate is lower than what was found in previous studies, but suggests that characteristics of the distal humerus are still quite valuable when estimating skeletal sex. More research is needed to assess reasons for the differential expression of these traits in different populations and to determine whether the method is nonpopulation specific.     

Development of discriminant functions to estimate sex in upper limb bones for mixed ancestry South Africans

South Africa has one of the highest murder rates in the world, which is associated with an increasing number of unidentified individuals. Forensic anthropologists can assist in these cases to reduce the number of potential victims the remains may belong to. Sex estimation potentially decreases the number of possible victims by half. The mixed ancestry population in South Africa is the second largest group of people; however, there remains a paucity of data and population-specific methods for sex estimation in this group. The aim of this study was to assess the potential for metrices obtained around the nutrient foramen and the maximum length of upper limb long bones to estimate sex in mixed ancestry South Africans using discriminant function analysis. A total of 328 humeri, radii and ulnae from individuals of mixed ancestry were analysed. Sex was correctly classified with an average classification accuracy of 84.3% in the humeri, 88.3% for radii and 83.5% for the ulnae. Total length was the single best predictor of sex; the combination of total length with dimensions related to the nutrient foramen produced high classification accuracies in the current study. Overall, sexual dimorphism was observed in mixed ancestry South Africans upper limb long bones. The findings of this study further emphasise the need for population-specific standards of sexing in an attempt to improve current methods of forensic identification of descendants.     

Population data on the AmpF/STR Identifiler loci in Africans and Europeans from South Africa

Allele frequencies of 15 short tandem repeat (STR) loci, D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818 and FGA, were determined for 98 unrelated Africans from South Africa and 98 unrelated Europeans from South Africa using the AmpFlSTR Identifiler PCR amplification kit. The genotype frequency distributions of the 15 STR loci were in the Hardy-Weinberg equilibrium for both populations.     

Morphine extraction in necrophagous insects remains for determining ante-mortem opiate intoxication.

To study the potential use of insects remains as toxicological indicators, we measured morphine in desiccated entomological materials using a radioimmunoassay method (Coat-A-Count Serum Morphine, Dade Behring, France) following enzymatic hydrolysis.First, enzymatic cuticle extraction of morphine (pronase digestion preceded by a 2h incubation with a dithiothreitol solution) was performed on various substrates (Calliphoridae puparial cases and desiccated adults, and desiccated pupae of Dermestidae) which were then tested to identify possible interferences with the radioimmunoassay procedure.This same procedure was performed on puparial cases and desiccated adults of Lucilia sericata (Diptera, Calliphoridae) previously reared on minced meat containing various morphine concentrations. Morphine was detected only in cuticle powder from insects reared on meats containing 100 and 1000mg/kg. Higher concentrations were measured in puparial cases. Rearings on psoas from eight heroin overdose victims confirmed previous experimental results.Remains of necrophagous insects, particularly puparial cases, are often preserved for a long time, and consequently can serve as late alternative specimens for toxicological analysis when suitable tissues are not available.     

On the non-equivalence of documented cadaver lengths to living stature estimates based on Fully's method on bones in the Raymond A. Dart Collection

Regression equations for stature estimation have been derived from documented cadaver lengths available as part of the demographic information in the catalogue of skeletonised remains in different collections around the world. The Raymond A. Dart Collection is one such collection, but the reliability of documented cadaver lengths in it has been previously questioned. The aim of this study was to compare these lengths with estimated living stature using Fully's anatomical method. Living stature was estimated with this method from a total of 156 complete skeletons obtained from the Collection. These heights were then compared with the documented cadaver lengths. It was observed that the documented cadaver lengths were significantly higher than the estimated living stature using Fully's method.     

A study of ethyl glucuronide in post-mortem blood as a marker of ante-mortem ingestion of alcohol

The possibility of post-mortem production of ethanol makes correct interpretation of ethanol detection in forensic autopsy samples difficult. Even though the levels of ethanol formed post-mortem are generally low, this may be highly relevant in cases where intake of alcohol was forbidden, for instance for pilots, professional drivers and countries with low legal alcohol limits for driving. Different criteria are used to determine whether a finding of ethanol is of exogenous origin, but there is no marker for alcohol ingestion that has been studied in detail. In this study, we wanted to evaluate the sensitivity and specificity of ethyl glucuronide (EtG), a direct minor metabolite of ethanol, measured in blood, as a marker of ante-mortem alcohol ingestion. Forensic autopsy cases were divided into groups with and without ante-mortem alcohol ingestion, according to strict inclusion criteria. In 93 cases with information on ante-mortem alcohol ingestion, EtG was detected in blood in all cases, even when levels of ethanol were low. In another 53 cases where there were no indications of ante-mortem alcohol intake, EtG could not be detected in blood in a single case, also in 11 cases in which ethanol was detected and considered to be most probably formed post-mortem. In conclusion, blood EtG determination seems to be a reliable marker of ante-mortem ingestion of alcohol, and it could be considered in forensic autopsy cases when post-mortem formation of ethanol is questioned.     

Estimation of stature from body parts

Anthropometric technique commonly used by anthropologists and adopted by medical scientists has been employed to estimate body size for over a hundred years. With the increasing frequency of mass disasters, the identification of an isolated lower extremity and the stature of the person it belonged to has created problems for the investigation of the identity of some of the victims. In spite of a need for such a study, there is a lack of systematic studies to identify fragmented and dismembered human remains. The purpose of the paper is to analyze anthropometric relationships between dimensions of the lower extremity and body height. Analysis is based on a sample of middle class male (N=203) and female (N=108) adult Turks residing in Istanbul. The participants are mostly students and staff members of a medical school, and military personnel. Measurements taken are stature, trochanteric height, thigh length, lower leg length, leg length, and foot height, breadth, and length. Of the five variables entered into the regression analysis, all but foot breadth participate in the analysis with leg length as the first and followed by thigh and foot lengths, and finally foot height in males (R(2)). There were also individually calculated formulae for some of these measurements which provided smaller R(2)-values. Student's t-test to assess if there was any intraobserver error in measurements take by individual anthropometrist did not show such any statistically significant difference. In conclusion, the study suggested that estimation of a living height can be made possible using various dimensions of the lower extremity. One must consider differences between populations in order to apply functions as such to others.     

Prediction of stature from hand measurements

A sample of 166 normal adult males and females was taken from different colleges of Assiut representing those living in upper Egypt. Each subject has been studied for measurements of stature (S), hand length (HL) and hand breadth (HB). The data were statistically analysed in order to assess the relationship between stature and hand measurements. The correlation matrix of the study indicates close similarity of the relationship between stature and hand measurements in both sexes and in both sides. A generalized multiple regression equation has been designed to estimate stature from values of hand length and hand breadth regardless of sex or side in the form: S = 34.5 + 5.77 HL + 2.7 HB +/- 5.1. This equation may be helpful to obtain approximate stature when there is difficulty in obtaining a direct measurement or where there is a chance print of a criminal or an amputated hand or arm.     

身高推断的法医学研究进展CSCD

个体身高推断是法医人类学个体识别的重要内容之一,目前常借助直接测量或放射学技术收集一定群体的四肢长骨、不规则骨、体表解剖标志的数据建立回归方程来实现。由于人口流动性的增加、人类体质整体提高的影响以及种族和地区间的差异,身高推断的研究应成为常规性研究。本文对不同身高推断方法进行回顾性综述,简要阐述各方法的优缺点,并展望身高推断的研究方向。     

New formulae for estimating stature in the Balkans

Recent studies of secular change and allometry have observed differential limb proportions between the sexes, among and within populations. These studies suggest that stature prediction formulae developed from American Whites may be inappropriate for European populations. The purpose of this investigation is to present more appropriate stature prediction equations for use in the Balkans to aid present-day identifications of the victims of genocide. The reference sample totals 545 white males obtained from World War II data. The Eastern European sample totals 177 males and includes both Bosnian and Croatian victims of the recent war. Mean stature for Eastern Europeans was obtained from the literature. Results show that formulae based on Trotter and Gleser systematically underestimate stature in the Balkans. Because Eastern Europeans are taller than American Whites it is appropriate to use this as an "informative prior" that can be applied to future cases. This informative prior can be used in predictive formulae, since it is probably similar to the sample from which the Balkan forensic cases were drawn. Based on Bayes' Theorem new predictive stature formulae are presented for Eastern Europeans.     

Stature- and age-related bias in self-reported stature.

The use of reported stature, especially self-reported stature such as on a driver's license, as a proxy for measured stature is necessary when measured stature is unavailable, for example, in matching data calculated from skeletal remains with data for missing persons. The accuracy of self-reported stature for older persons and especially for tall and short people is not well ascertained. Examination of published reports provides evidence that beginning at age 45, people compound their stature overestimation by an additional amount related to age (women by twice the amount of men). Analysis of anthropometric data from 8000 U.S. Army personnel indicates that the amount of general overestimation of stature by men is 2 1/2 times greater than that by women. Neither tall men nor tall women underestimate their stature, but men in the upper third of the stature range, and women in the upper 10%, self-report their stature with greater accuracy. No trends in accuracy are apparent in the remainder of the stature spectrum for men or women.