The talus: sex assessment of prehistoric New Zealand Polynesian skeletal remains

Prehistoric Polynesian skeletal remains are frequently being recovered in New Zealand due to the increasing pace of urbanisation. Since such material must often be reinterred quickly, it is important that the sex of individuals be determined from the remains in a relatively short time. For this purpose, discriminant function analysis was utilised for sex determination of prehistoric adult New Zealand Polynesian tali (24 males and 27 females). Five measurements were taken and subjected to Statistical Package for the Social Sciences (SPSS) discriminant function analysis. For the discriminant functions derived, accuracy of sex determination ranged from 85.1 to 93.3%. Reduction in error over random assignment by sex ranged from 70 to 87%.     

The calcaneus: sex assessment of prehistoric New Zealand Polynesian skeletal remains

The increasing pace of urbanisation has meant that prehistoric Polynesian skeletal remains are frequently being recovered in New Zealand. Since such material must often be reinterred quickly, it is important that the sex of individuals be determined from the remains in a relatively short time. For this purpose, discriminant function analysis was utilised for sex determination of prehistoric adult New Zealand Polynesian calcanei (26 male and 22 female). Five measurements were taken and subjected to Statistical Package for the Social Sciences (SPSS) discriminant function analysis. For the discriminant functions derived, accuracy of sex determination ranged from 88.4 to 93.5%. Reduction in error over random assignment by sex ranged from 77 to 87%.     

The femoral head: sex assessment of prehistoric New Zealand Polynesian skeletal remains

Prehistoric Polynesian skeletal remains are frequently being recovered in New Zealand due to the increasing pace of urbanisation. Since such material must often be reinterred quickly, it is important that the sex of individuals be determined from the remains in a relatively short time. For this purpose, discriminant function analysis was utilised for sex determination of prehistoric adult New Zealand Polynesian femora (47 male and 44 female). Three measurements of the femoral head were taken and subjected to Statistical Package for the Social Sciences (SPSS) discriminant function analysis. For the discriminant functions derived, accuracy of sex determination ranged from 80.9% to 82.4%. Reduction in error over random assignment by sex ranged from 62% to 65%.     

The articular surfaces of the hindfoot: sex assessment of prehistoric New Zealand Polynesian skeletal remains

Prehistoric Polynesian skeletal remains are frequently being recovered in New Zealand due to the increasing pace of urbanisation. Since such material must often be reinterred quickly, it is important that the sex of individuals be determined from the remains in a relatively short time. For this purpose, discriminant function analysis was utilised for sex determination of prehistoric adult New Zealand Polynesian tali (24 male and 27 females) and calcanei (26 males and 22 females). Two measurements of the trochlear articular surface of the talus and two measurements of the posterior talar articular surface of the calcaneus were taken and subjected to Statistical Package for the Social Sciences (SPSS) discriminant function analysis. For the single discriminant function derived, accuracy in sex determination was 92.3% and reduction in error over random assignment by sex was 85%.     

Estimation of sex by 3D CT measurements of the foramen magnum

The purpose of this prospective study is to investigate the value and accuracy of the measurements of the foramen magnum (FM) by using three-dimensional computed tomography (3DCT). Cases were randomly selected among 100 patients (48 males, 52 females) who had temporal CT in the Radiology Department. Seven measurements of the foramen magnum on 3D images, modified from the nine lines previously defined by Giles and Elliot were made. Using Fisher's linear discriminant functions test, the length and width of right condyle and width of FM diameters were found to be statistically different in each sex (p < 0.001) with 81% accuracy. To our best knowledge, this is the first report studying 3DCT measurements of FM, resulting with a sex determination accuracy rate of 81%. CT/3DCT can be reliably used in further investigations to provide basis for anthropometric and forensic issues.     

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.     

Articular surfaces of the pectoral girdle: sex assessment of prehistoric New Zealand Polynesian skeletal remains

Prehistoric Polynesian skeletal remains are frequently being recovered in New Zealand due to the increasing pace of urbanisation. Since such material must often be reinterred quickly, it is important that the sex of individuals be determined from the remains in a relatively short time. For this purpose, discriminant function analysis was utilised for sex determination of prehistoric adult New Zealand Polynesian clavicles (31 male and 31 female) and scapulae (33 male and 38 female). Diameters of the acromial and sternal ends of the clavicle and the height and breadth of the scapular glenoid cavity were measured and subjected to Statistical Package for the Social Sciences (SPSS) direct discriminant function analysis. For the single discriminant function derived, accuracy of sex determination was 97.7% and reduction in error over random assignment by sex was 95%. This discriminant function will be a useful tool in the assessment of human remains in the forensic and archaeological context because it incorporates measurements which can be taken on incomplete bones.     

Testing the validity of metacarpal use in sex assessment of human skeletal remains

To assess the potential of employing metacarpals in assessing sex of human skeletal remains, previous investigators have generated regression equations (Scheuer & Elkington, 1995) and linear discriminant functions (Falsetti, 1995; Stojanowski, 1999) based upon measurements from metacarpals. Results have varied in overall accuracy and which metacarpal produces the greatest accuracy. Using a contemporary sample, this study seeks to evaluate the validity of using metacarpals to assign sex by testing methodologies of previous studies. Measurements defined by previous authors were repeated on metacarpals from 23 adult cadavers and data were subjected to regression equations and linear discriminant analysis according to previous methodologies. Accuracy in sex determination from methods of Scheuer & Elkington (1993) and Falsetti (1995) were lower than originally reported while accuracy from methods of Stojanowski (1999) were higher than previously reported. These results suggest that the use of metacarpals in sex determination may be limited and should be applied cautiously.     

面颅的种族差异性研究

目的探索面颅在中国黄种人与欧洲白种人种族鉴定方面的差异性。方法通过对150例中国黄种人和欧洲白种人样本(各75例)面颅骨的观测、分析,选取与种族变化关系密切的51项观测指标进行观测,使用SPSS16.0软件对观测数据逐级进行统计学分析、处理,建立判别方程。从研究样本外随机抽取白种人和黄种人各10例标本进行盲测。结果筛选出7项测量结果相对稳定、种族差异较大指标建立全指标、逐步和多指标判别函数方程共5对,综合判别率在73.2%~89.8%。盲测正确率在75%~95%,结果令人满意,说明判别方程稳定、可靠,对种族鉴别的应用性较好。结论本研究所建立的种族判别方程可应用于中国黄种人与欧洲白种人的种族鉴定。     

Sex Assessment from the Sacral Base by Means of Image Processing

Abstract:  To help improve sex assessment from skeletal remains, the present study considers the diagnostic value of the sacral base (basis osseus sacri) based on its planar image and related metric data. For this purpose, 114 adult sacra of known sex and age from two early 20th century Italian populations were examined, the first from Bologna, northern Italy ( n  = 76), and the second from Sassari, Sardinia ( n  = 38). Digital photos of the sacral base were taken with each bone in a standardized orientation. Technical drawing software was used to trace its profile and to measure related dimensions (area, perimeter, and breadth of S1 and total breadth of the sacrum). The measurements were subjected to discriminant and classification function analyses. The sex prediction success of 93.2% for the Bolognese sample, 81.6% for the Sassarese sample, and 88.3% for the pooled sample indicates that the first sacral vertebra is a good character for sex determination.     

Sex determination of Chinese femur by discriminant function

The objective of this study was to provide a method of sex determination for Chinese femur, especially for fragmentary remains. Statistical analysis of 17 measurements based on 141 northeastern Chinese femora shows that all measurements have significant sex differences. Sex determination by the midpoint method of a single measurement can obtain an average accuracy of 76.8%. The results indicate that of all dimensions the maximum head diameter is the best discriminator of sex. It alone can determine the sex of a femur with 85.1% accuracy. The results also show that maximum head diameter, transverse head diameter, epicondylar breadth, upper breadth, and medial condylar length have higher sexual dimorphisms than the dimensions of length. According to the result to stepwise discriminant analysis and the need for sexing fragmentary remains, 22 discriminant functions composed of various combinations of variables were calculated which can determine the sex of the femur correctly 82.3 to 87.2%. The methods of sex determination provided by this paper can be used to sex poorly preserved femora.     

Sexual dimorphism in the humerus: a comparative analysis of Chinese, Japanese and Thais

Determination of sex from the skeleton is vital to medicolegal investigations. There is no longer any question that populations differ in size and proportions and these differences affect the metric assessment of sex. The extent of variation in sexual dimorphism among Asian Mongoloids within and between regions has not been quantified by discriminant function analysis, nor have standards for most groups been introduced for the humerus. Therefore, the purpose of this research is to establish metric standards for sex determination from the humerus of Chinese, Japanese and Thais, as well as to compare size and sexual dimorphism in these Asian Mongoloid populations. The database for this study consisted of documented skeletal samples from China (N = 87), Japan (N = 90), and Thailand (N = 104). Six standard dimensions, including maximum length, vertical head diameter, minimum midshaft diameter, maximum midshaft diameter, midshaft circumference, and epicondylar breadth were taken and subjected to stepwise and direct discriminant function analysis. Of dimensions selected by the stepwise function, vertical head diameter and epicondylar breadth were the only elements common to all three groups. Overall, mean accuracies were highest using formulae produced by the stepwise procedure and ranged from 86.8% in the Chinese to 92.4% in the Japanese to 97.1% in the Thais. Group comparisons also revealed that while the Chinese had the largest measurements, they were the least dimorphic. The reverse was true for the Thais and the Japanese were intermediate on both counts. In cross validation tests, classification accuracy decreased in all cases where a formula from one group was applied to another. It was therefore concluded even though all individuals were Asian Mongoloids, these regionally diverse populations exhibited significant metric differences that affect sex determination from the skeleton. These findings confirm those of previous studies that there is a need for group specific metric standards of assessment.     

Identification of sex depending on radiological examination of foot and patella

Forensic anthropology involves the building of an antemortem profile of an individual from skeletal remains. This includes sex, race determination, and age and stature estimation. Because most bones that are conventionally used for sex determination are often recovered either in a fragmented or incomplete state, it has become necessary to use denser bones that are often recovered intact, eg, the patella, calcaneus, and talus. The present work was performed to investigate the possibility of estimation of sex from some radiologic measurements among a known cross-section of Egyptian population. In this study lateral and anteroposterior radiographs of the right foot and knee were made on 160 living unfractured and nonpathologic individuals comprising 80 males and 80 females aged 25 to 65 years referred to the Radiology Department of Assiut University Hospital. Two measurements on right patella (maximum height and maximum width) and 2 measurements of metatarsal bones (length and midshaft diameter), were used to determine sex by univariate and multivariate discriminant analysis. Eighty radiographs of foot and patella of individuals not used in the original sample were randomly selected to test the accuracy of this method. The study revealed that significant sex differences were demonstrated based on these measurements taken on metatarsal bones more than on patella. One function associating 2 parameters (length and midshaft) of the third metatarsal bone obtained the highest value of correct sex determination with rate of 100% accuracy. The multivariate function associating length of the first, third, and fifth metatarsal bones and midshaft of first, second, and fifth metatarsal gave 100% accuracy. Test of multivariate function on the independent sample revealed a correct classification of 87.5%.     

Discriminating sex in South African blacks using patella dimensions

For many years, sex determination has been carried out on skeletal remains to identify individuals in forensic cases and to assess populations in archaeological cases. Since it has been shown that not all bones are found in a forensic case, discriminant function equations should be derived for all bones of the body to assist in sex determination. Numerous studies have shown the usefulness of bones of the lower extremity (e.g. femur, tibia) in sex determination using discriminant function analysis, but the use of patella measurements has not been extensively investigated for this purpose. It is therefore the aim of this study to derive discriminant function equations for sex determination from measurements of the patella of South African blacks as represented in the Raymond A. Dart Collection of Human Skeletons. A total sample of 120 (60 male, 60 female) patellae were measured using six measurements. The Statistical Product and Service Solutions (SPSS) program was used to derive the equations. Stepwise and direct analyses were performed with the highest rate of classification of 85% thereby making the patella useful for sex determination. Thus, the proposed equations derived from this study should be used with caution and only on the South African black population group.     

An assessment of the accuracy of discriminant function equations for sex determination of the femur and tibia from a South African population

The purpose of this study is to test the accuracy of seven discriminant function equations that have been derived by Steyn and Is?an for sex determination using measurements of the femur and tibia of South Africans of European descent (SAED). While the validity of some of the discriminant functions has been assessed by the authors who derived them, no previous independent study has been carried out to assess the accuracy of these equations. These equations have not been tested on skeletons located outside of the Gauteng province. A suite of measurements were taken on 272 femora and 256 tibiae obtained from four South African skeletal collections. The validity of each of the previously published equations for the femur was confirmed. However, two functions of the tibia showed low accuracy rates, most likely due to difficulties in recording the distal epiphyseal breadth measurement, and thus were found to be poor assessors of sex.     

Determination of sex for the 12th thoracic vertebra by morphometry of three-dimensional reconstructed vertebral models

Thirty-three linear measurements and two ratios were derived from 102 12th thoracic vertebrae of the Digital Korean database at the Catholic Institute for Applied Anatomy. Of 35 linear traits, 23 were sexually dimorphic. We created 23 discriminant function equations that predicted sex with 62.7-85.3% accuracy. The analysis using combinations of two factors gave higher accuracies: most equations with accuracies over 80% included at least one measurement involving the coronal diameter of the vertebral endplate. Using stepwise method of discriminant function analysis, three variables predicted sex with 90.0% accuracy: the coronal diameter of the superior endplate of the vertebral body, the ratio of anterior to middle height of the body, and the length of the left mammillary process and pedicle. Coronal dimensions of the vertebral body represented the major sex difference. These equations will help forensic discrimination of the sex of this vertebra among Koreans.     

Metric sex determination from the pelvis in modern Greeks

The ability to determine sex from unknown skeletal remains is vital, and methods to do this on the various bones of the human skeleton have been researched extensively. Many researchers have emphasized the need for population specific data for methods which are based on measurements, as there are vast differences in body size in various populations. The pelvis is known to be the most sexually dimorphic part of the human body, and no discriminant function formulae for this bone are available for Greek or other Mediterranean groups. The purpose of this study was therefore to develop discriminant functions which can be used for sex determination on measurements of the pelvis of modern Greeks. A sample of 97 male and 95 female pelves in a skeletal collection housed in Heraklion, Crete, was used. Measurements were taken from the articulated pelvis, single os coxae and the sacrum. Discriminant function formulae for all measurements and various combinations were used in order to assess the degree of sexual dimorphism in various parts of the pelvis, and to make the formulae usable on fragmented remains. For the single os coxae, average accuracies of 79.7-95.4% (79.1-93.5% on cross-validation) were found. However, it was found that measurements of the sciatic notch were unreliable and yielded poor results, and it is advisable that this characteristic must only be used as a last resort. Dimensions of the sacrum were not very dimorphic (average accuracy 60.9%), while measurements from the articulated pelvis yielded poorer results than that from single innominate bones. The diameter of the acetabulum was the single most dimorphic characteristic, providing on average 83.9% accuracy when used in isolation.     

Virtual determination of sex: metric and nonmetric traits of the adult pelvis from 3D computed tomography models

Examination of the adult os coxae and sacrum is one of the most common methods of sex estimation from bone. Medical imaging, such as computed tomography (CT), provides the opportunity for three-dimensional (3D) imaging of the skeleton from clinical scans of known individuals in situ. In this study, a randomly selected subset of abdominopelvic CT-derived models were used to evaluate simple, repeatable metric methods of sex estimation based on a combination of obstetric measurements and the traditionally nonmetric Phenice-derived traits. A four-variable discriminant function for sex estimation was developed based on statistical analyses. Overall, the cross-validated accuracy of this method was 100%, with inter-observer error showing an average of only 2.2%. Comparative analysis was run on the data set using FORDISC 3.0. This study shows that current sex determination standards from the pelvis should be updated to include more in vivo data to increase the accuracy of identification.     

Metric analysis of sex differences in South African black and white pelves

Sex determination of unknown skeletal material is one of the most vital determinations made by forensic anthropologists. Numerous studies have focussed on the differences, both osteometric and morphological, between the sexes of a particular racial phenotype and population. Previous work by a variety of researchers has underscored the necessity of population specific standards. The purpose of this research is to metrically assess sex differences in the pelvis of South African whites and blacks and develop standards tailored to these groups. Data were collected from 400 known sex/race skeletons from the Pretoria and Dart Collections. Nine measurements (traditional and newly developed) were taken and subjected to SPSS stepwise and direct discriminant analysis. Results indicated that there are significant differences (p < or = 0.001) between the sexes of both races for most measurements. Discriminant function analysis selected ischial length as the most sexually dimorphic dimension in whites (averaged 86% accuracy), while acetabulum diameter was most diagnostic in blacks (averaged 84% accuracy). Six functions were developed from the pelvic dimensions. Highest accuracy was achieved from Function 1 (including all dimensions) which averaged 95.5% correct classification in whites and 94% in blacks. Functions based on selected parts of the pelvis were not as effective and ranged from 73-86% in whites and 72-84% in blacks. This research provided evidence of the significant sex differences that exist between the pelves of South African whites and blacks whilst measurements used here for discriminant function analysis gave classifications with high accuracies. These results can be used to aid in the identification of human skeletal remains in South Africa.     

Studying survivors of near-lethal suicide attempts as a proxy for completed suicide in prisons

Sex determination is a necessary step in the investigation of unidentified human remains from a forensic context. Teeth, as one of the strongest tissues in the human body, can be used for this purpose. Most studies of sexual dimorphism in teeth are based on the traditional mesiodistal and buccolingual crown measurements. The purpose of this study is to examine the degree of sexual dimorphism in permanent molars of modern Greeks using crown and cervical diagonal diameters, and to evaluate their applicability in sex determination. A total of 344 permanent molars in 107 individuals (53 male and 54 female) from the Athens Collection were examined. Crown and cervical diagonal diameters of both maxillary and mandibular molars were measured. It was found that males have larger molars than females and in 19 out of 24 dimensions measured male molars exceeded female molars significantly (P<0.05). The most dimorphic molars are the maxillary second molar, and the mandibular second and first molars. Although other molars were also sexually dimorphic they did not have a statistically significant difference in all dimensions. Cervical diagonal diameters have found to be more sexually diamorphic than crown diagonal diameters. In discriminant function analysis the variables entered more frequently were the cervical diagonal diameters mainly of mandibular molars. Classification accuracy was found to be 93% for the total sample, 77.4% for upper jaw, and 88.4% for the lower jaw. Accuracy rates were higher for cervical than crown diagonal diameters. The data generated from the present study suggest that this metric method can be useful and reliable for sex determination, especially when the traditional dental measurements are not applicable.