Determination of sex from the hyoid bone in a contemporary White population

Six discriminant functions, developed from an historic White population, were tested on a contemporary White population for determination of sex from the hyoid. One hundred and thirty four fused and unfused hyoids from a contemporary White population were used. Individuals ranged between 20 and 49 years old. Six historic White discriminant functions were applied to the fused and unfused hyoids of the pooled contemporary White population, i.e. all males and females and all age ranges combined. The overall accuracy rates were between 72.1% and 92.3%. Correct sex determination for contemporary White males ranged between 88.2% and 96.3%, while correct sex determination for contemporary White females ranged between 31.3% and 92.0%. Discriminant functions were created for the contemporary White population with overall mean accuracy rates between 67.0% and 93.0%. The multivariate discriminant function overall accuracy rates were between 89.0% and 93.0% and the univariate discriminant function overall accuracy rates were between 67.0% and 86.8%. The contemporary White population data were compared to other populations and showed significant differences between many of the variables measured. This study illustrated the need for population-specific and temporally-specific discriminant functions for determination of sex from the hyoid bone.     

Estimation of sex based on patella measurements in a contemporary Chinese population using multidetector computed tomography: An automatic measurement method

Sex estimation is an important part of creating a biological profile, and ultimately assisting in creating a presumptive identification of unidentified skeletal remains. However, manual methods of anthropometric are time-consuming and prone to observer variability. The present study is an attempt to estimation of sex from automatic measurement of patella by multidetector computed tomography (MDCT) in a contemporary Chinese population. Four measurements for every patella, including maximum height (MAXH), maximum breadth (MAXB), maximum thickness (MAXT) and patellar volume (PV), were automatically provided by the software from CT image of 300 Chinese. The sample is composed of 156 males and 144 females with an average age of 41.44 and 45.68 years, respectively. The statistical analyses showed that all variables were sexually dimorphic. Receiver operating characteristic (ROC) analysis was performed to estimate sex from patella. The univariate analysis of each patellar parameter yielded a sex classification accuracy rate of 73.1% to 85.7%. The classification accuracy rates of sex estimation using the combination of the patellar parameters are 81.9% to 91.6%. This paper provides indications that the patella is important bone for sex estimation and it may be used as an alternative in forensic cases when the skull and pelvis are unavailable.     

Sex determination from talus in Chinese population by three-dimensional measurement approach

ObjectiveThe determination of sex is an essential part of building the biological profile for unknown human remains. Sex determination from talus in Chinese population has been rarely reported. The aim of this study was to determine sex by discriminant function analysis through talus measurement in Chinese population.Methods48 male and 47 female Chinese northeast subjects were taken in this research. The ankle joints of these subjects were scanned by CT. In total, thirteen indexes were measured through Mimics and Magics software. Length and breadth indexes of total talus, trochlea, talar head, medial and lateral malleolus articular surface were mainly selected. Nine of them were measured through Mimics software. The other four indexes were measured through Magics software. All data were analyzed by independent-samples t-test in SPSS and Stata software. Discriminant function equations were generated for sex determination.ResultsAll the indexes were normally distributed. No significant difference between left and right talus in either males or females was identified (P > 0.05). All results showed significant sexual difference (P < 0.05) except posterior breadth of trochlea. The average accuracy of sex determination ranged from 95.85% to 98.45% in the direct method and 98.95% in the stepwise method.ConclusionsLength indexes showed higher accuracy rate than breadth ones. Length of lateral malleolus articular surface was the best discriminator of sexual dimorphism. Talus was proved effective for sex determination in Chinese population. This study provided a remarkable reference for sex determination in forensic science.     

Estimating height from the first and second cervical vertebrae in a Spanish population

One of the roles of forensic anthropology is the identification of skeletal remains and over the years many methods have been developed to obtain specific details of a corpse such as an estimation of age and height. The femur and tibia are ideal for this purpose but unfortunately they are often missing or badly fragmented. For this reason, in this present study, we used the smaller bones of the first and second cervical vertebrae, which are often better preserved than the long bones. Direct measurement of these bones has been found to be misleading, largely due to the remains of a covering of soft tissue, and to overcome this all measurements were taken from tomographic images. The aim of this study is to provide an auxiliary diagnostic method to evaluate the association of different anthropometric measurements taken with tomographic imagery of both the first cervical and second cervical vertebra with body height within a sample of the Spanish population.Measurements were taken from tomographic images taken with a dental CT of 203 healthy individuals from a Spanish population. The best correlation was obtained in the case of unknown sex using four measurements: two of the first cervical vertebra and two of the second vertebra using the following regression formula S = 49.02 + 1.02O + 1.58DO + 0.49V + 0.67I.All formulae provided statistically significant results and can be applied to any skeletal remains belonging to a Spanish population.     

Topological variability and sex differences in fingerprint ridge density in a sample of the Sudanese population

Fingerprints are important biometric variables that show manifold utilities in human biology, human morphology, anthropology, and genetics. Their role in forensics as a legally admissible tool of identification is well recognized and is based on their stability following full development, individualistic characteristics, easy classification of their patterns, and uniqueness. Nevertheless, fingerprint ridge density and its variability have not been previously studied in the Sudanese population. Hence, this study was conducted to analyze the topological variability in epidermal ridge density and to assess the possibility of its application in determining sex of Sudanese Arabs. The data used for this study were prints of all 10 fingers of 200 Sudanese Arab individuals (100 men and 100 women) aged between 18 and 28 years. Fingerprint ridge density was assessed for three different areas (radial, ulnar and proximal) for all 10 fingers of each subject. Significant variability was found between the areas (p < 0.01). Women showed significantly higher ridge density in the three areas for all and each fingers. Men and women showed similar patterns of densities with distal areas being denser than proximal ones. Side asymmetry was more evident in distal areas. Ridge density thresholds for discrimination of sexes were developed. Hence, fingerprints found in forensic examinations/crime scenes can be useful to determine sex of Sudanese individuals based on fingerprint ridge density; furthermore, ridge density can be considered a morphological trait for individual variation in forensic anthropology.     

Sex estimation using diagonal diameter measurements of molar teeth in African American populations

Teeth are often recovered in forensic cases due to their postmortem longevity. The goal of the present research was to investigate the degree of sexual dimorphism in the permanent molars of African Americans using crown and cervical diagonal diameters. Discriminant functions developed from a modern Greek population were tested for accuracy of sex estimation in an African American population. One hundred and three (53 males and 50 females) individuals ranging in age from 16 years to 66 years old were used from the Robert J. Terry Anatomical Skeletal Collection. Four diagonal diameter measurements were taken for each of the left mandibular and maxillary molars: mesiobuccal-distolingual crown diameter, mesiolingual-distobuccal crown diameter, mesiobuccal-distolingual cervical diameter, and mesiolingual-distobuccal cervical diameter. The overall percentage of accuracy of the modern Greek discriminant functions when applied to the African American sample was between 53.8% and 63.6%. Males were more accurately classified (93.6%–100%) than females (0%–18.2%). The African American population specific direct discriminant functions showed accuracy rates from 72.6% to 100% for the original data and 40%–72.3% for the cross-validated data. The African American stepwise discriminant functions showed accuracy rates from 63.9% to 77.6% for the original and cross-validated data. Comparisons to other populations were made. The results suggest that, in teeth, there is variation in the degree of sexual dimorphism between populations and discriminant functions for sex estimation in dentition are population specific.     

Estimation of sex from the upper limb measurements of Sudanese adults

Sex estimation is the first biological attribute needed for personal identification from mutilated and amputated limbs or body parts in medical-legal autopsies. Populations have different sizes and proportions that affect the anthropometric assessment of sex. Relatively few published works assess the accuracy of sex estimation from soft tissue measurements of upper limb parts, except for the hand and its components, but these studies involve a limited range of global populations. The current study aimed to assess the degree of sexual dimorphism in upper limb measurements and the accuracy of using these measurements for sex estimation in a contemporary adult Sudanese population. The upper arm length, ulnar length, wrist breadth, hand length, and hand breadth of 240 right-handed Sudanese subjects (120 males and 120 females) aged between 25 and 30 years were measured by international anthropometric standards. Demarking points, sexual dimorphism indices and discriminant functions were developed from 200 subjects (100 males and 100 females) who composed the study group. All variables were sexually dimorphic. The ulnar length, wrist breadth and hand breadth significantly contributed to sex estimation. Forearm dimensions showed a higher accuracy for sex estimation than hand dimensions. Cross-validated sex classification accuracy ranged between 78.5% and 89.5%. The reliability of these standards was assessed in a test sample of 20 males and 20 females, and the results showed accuracy between 77.5% and 90%. This study provides new forensic standards for sex estimation from upper limb measurements of Sudanese adults.     

Sexual dimorphism of acetabulum-pubis index in South-Indian population

Accurate sexing of skeletal remains is a vital part of any medicolegal investigation and a challenge to physical anthropologists. Hipbone is considered as the most reliable sex indicator in the human skeleton. Standards of morphological and morphometric sex differences in the skeleton may differ with the population sample involved and thus cannot be applied universally. The acetabulum-pubis index (A-P index) which is one of the reliable criteria for sex differentiation of human hipbones is derived from the measurements of acetabulum diameter and the distance between its anterior rim and symphysis pubis. Sixty-seven adult hipbones of known sex (36 males and 31 females) belonging to South-Indian population were studied to investigate sexual dimorphism of the well established A-P index. The index below 77.5 identified 81% of females and above 77.5 identified 83% males accurately.     

Morphometric evaluation of the foramen magnum for sex determination: A study from Saudi Arabia

The present study provides a database of various morphometric dimensions of the foramen magnum region in the Saudi population. The objective of this study was to evaluate various measurements of the foramen magnum region for sex determination in the Saudi population by using computed tomography (CT) images. The various radiological measurements of the foramen magnum region were measured in a total of 200 adult subjects of Saudi origin including 100 males and 100 females. Sexual dimorphism was observed in five parameters related to the foramen magnum, namely length of the right occipital condyle (LROC), length of the left occipital condyle (LLOC), width of the foramen magnum (WFM), area of the foramen magnum (AFM) and length of the foramen magnum (LFM). The accuracy to discriminate sex ranged from 65.5% to 62.5% when LROC, LLOC, WFM, AFM, and LFM were considered as individual parameters. When multiple parameters were combined to discriminate sex, the highest accuracy of 71% was achieved.     

Reliability of mandibular canine and mandibular canine index in sex determination: A study using Uyghur population

Sex determination is a key process that is required to establish the forensic profile of an individual. Mandibular canine index (MCI) method yields fairly positive results for sex determination. However, this method has been challenged by a few authors. This study aimed to examine the reliability of MCI in Chinese Uyghur population and to establish its normal value for this ethnic group. Dental casts of 216 students (117 males and 119 females) from the College of Stomatology of Xinjiang Medical University in China were used to determine the sexing accuracy of MCI. The mesiodistal (MD) dimension of mandibular canine crowns, the inter-canine distance, and the MCI were calculated. The accuracy of the standard MCI derived from the current data was compared with that of the standard MCIs derived from previous data. Results were statistically described using the independent-samples t-test. The MD dimension of mandibular crown, the inter-canine distance, and the MCI exhibited statistically significant sexual dimorphism. Sex determination using the MCI derived from the current data revealed fairly reliable results. Therefore, MCI is a reliable method for sex determination for Uyghur population, with 0.248 as standard MCI value.     

Sex determination from carpal bone volumes: A Multi Detector Computed Tomography (MDCT) study in a Malaysian population

PurposeThe use of Multi Detector Computed Tomography (MDCT) volume measurements of bones for sex determination allows fragile, fragmented human remains to be assessed without compromising the specimen. We set out to assess the ability of MDCT carpal bone volume measurement in determining sex in a Malaysian population.Materials and methods52 healthy volunteers were scanned in a 16-slice MDCT, and the volume of 104 sets of carpal bones was measured using a Syngo workstation (Both CT and workstation-Siemens Healthcare, Erlangen, Germany).ResultsMale carpal bones were of higher volume compared to the female carpal bones (p < 0.001). Area under the curve (AUC) assessment of responder-operator characteristics curves showed that the trapezium bone was best able to predict sex with an AUC of 0.986. At a trapezium bone volume of ⩾1.94 cm³, there was a 93.5% probability that the subject was male. Binary logistic regression analysis found that the highest accuracy was derived using the pisiform, trapezium and capitate bones. There was a strong relationship between sex prediction and grouping of the carpal bone volumes (Nagelkerke R² = 0.923) with an overall prediction accuracy of 97%.ConclusionAll 8 carpal bones exhibit sexual dimorphism to varying degrees. A binary regression analysis combining the 5 carpal bones with the highest predictive values for sex produces an accurate predictive model.     

Population specificity in the estimation of skeletal age and sex: case studies using a Western Australian population

ABSTRACT

The expertise of the forensic anthropologist is grounded in the study of skeletal morphology relative to normal state; the latter is variously defined according to the complex interrelationship between biological function, genetics and intra-specific variation (amongst others). In relation to sex estimation, there are multiple dimorphic attributes in the adult skeleton that facilitate accurate sex estimations. It is, however, well established that there are population specific influences in not only skeletal growth, but also the expression and magnitude of sexual dimorphism (notwithstanding relative consistency in ‘universally dimorphic traits’ that relate to biological functioning – e.g., pelvic shape in relation to female functional requirements for childbirth).

The recognition of the need for statistical quantification of forensic assessment is mandated by judicial requirement. Application of reference standards ‘foreign’ to that of the local jurisdiction, however, introduces an unknown variation and by association possible misclassifications. The present paper aims to empirically demonstrate the effect of the latter in a Western Australian population using multivariate classification statistics. We report here the analysis of a sample comprising three-dimensionally reconstructed cranial (n = 400) and pelvic (n = 400) multi-detector computed tomography (MDCT) thin-slice scans. In the morphometric analysis of cranial dimorphism, we demonstrate an unacceptably large sex bias; foreign standards thus frequently misclassify females.     

A fully automated sex estimation for proximal femur X-ray images through deep learning detection and classification

PurposeTo develop a fully automated deep learning pipeline using digital radiographs to detect the proximal femur region for accurate automated sex estimation.MethodRadiograph predictive features from 2122 Chinese Han clinical pelvic with ages ranging from 18 to 26 years were collected retrospectively to train and test the sex prediction model using deep machine learning’s convolutional neural networks (CNN). Model performance was assessed using a Chinese Han population with 361 samples and a white population with 50 samples. The average accuracy of the sex estimation of the two test datasets was determined.ResultsFor the Chinese Han population test dataset, the sex estimation accuracy was 94.6% (males: 93.9% and females: 94.7%). For the white population samples, the accuracy of sex estimation was 82.9% (males: 80.9% and females: 88.6%). The accuracy of CNN tested in the Chinese population was significantly higher than that tested in the White population (p < 0.001)ConclusionsThe model based on convolutional neural networks has an accuracy similar to that of current state-of-the-art mathematical functions using manually extracted features for the Chinese Han population samples, proving to be a reliable choice for the human sex estimation.     

Cranio-facial bones evaluation based on clinical CT data for sex determination in Northwest Indian population

The skull and pelvis have been the first choice of bones for determination of unknown human remains. The goal of the present study was to derive discriminant function equations by using clinical CT scan data of cranio-facial bones for sex determination in Northwest Indian population. This study was conducted at Department of Radiology, by collecting the retrospective data of CT scan of 217 samples. In the data, 106 were males and 111 were females in the age group between 20 and 80 years. The total number of parameters under investigation were 10. All the selected variables were sexually dimorphic and showed significant values. 91.7% of original grouped cases were correctly classified to their sex category. The TEM, rTEM and R were under the acceptable limits. The univariate, multivariate and stepwise discriminant function analysis recorded an accuracy of 88.9%, 91.7% and 93.6% respectively. Multivariate direct discriminant function analysis stepwise method yielded the highest level of accuracy in differentiating males and females. All the variables reflected statistically significant difference between males and females (p less than 0.001). The best single parameter with highest level of sexual dimorphic trait was length of cranial base. This study aims to provide sex assessment using clinical data of CT scan in Northwest Indian population by incorporating the BIOFB cranio-facial parameter. The morphometric measurements taken on CT scan images can be utilized by forensic experts in identification process.     

Human bony labyrinth as a sex indicator in subadults

Due to the durability and good preservation of the petrous bone in archaeological and forensic contexts, the value of the inner ear as a sex indicator has been evaluated in various studies. Previous findings suggest that the morphology of the bony labyrinth is not stable in the postnatal period. In this study, we aim to assess the sexual dimorphism of the bony labyrinth via analysis of computed tomography (CT) data obtained from 170 subadults (birth to 20 y.o.) and test whether the postnatal changes of the bony labyrinth affect the level of dimorphism in the inner ear. A set of 10 linear measurements of 3D labyrinth models as well as 10 size and shape indices were analyzed. Sexually dimorphic variables were used to produce sex estimation formulae with discriminant function analysis. The produced formulae allowed for the correct classification of up to 75.3 % of individuals aged from birth to 15 years old. Sexual dimorphism was not significant for individuals between 16 and 20 years of age. This study suggests that the morphology of the subadult bony labyrinth exhibits significant sexual dimorphism in individuals under 16 years of age, which can aid the forensic identification process. Although postnatal growth of the temporal bone seems to affect the level of sexual dimorphism present in the inner ear, the formulae created in this study could be used as an additional tool for sex estimation of subadult (<16 y.o.) remains.     

Body height estimation from post-mortem CT femoral F1 measurements in a contemporary Swiss population

PurposeThe present study aimed at the comparison of body height estimations from cadaver length with body height estimations according to Trotter and Gleser (1952) and Penning and Riepert (2003) on the basis of femoral F1 section measurements in post-mortem computed tomography (PMCT) images.MethodsIn a post-mortem study in a contemporary Swiss population (226 corpses: 143 males (mean age: 53 ± 17 years) and 83 females (mean age: 61 ± 20 years)) femoral F1 measurements (403 femora: 199 right and 204 left; 177 pairs) were conducted in PMCT images and F1 was used for body height estimation using the equations after Trotter and Gleser (1952, “American Whites”), and Penning and Riepert (2003).ResultsThe mean observed cadaver length was 176.6 cm in males and 163.6 cm in females. Mean measured femoral length F1 was 47.5 cm (males) and 44.1 cm (females) respectively. Comparison of body height estimated from PMCT F1 measurements with body height calculated from cadaver length showed a close congruence (mean difference less than 0.95 cm in males and less than 1.99 cm in females) for equations both applied after Penning and Riepert and Trotter and Gleser.ConclusionsFemoral F1 measurements in PMCT images are very accurate, reproducible and feasible for body height estimation of a contemporary Swiss population when using the equations after Penning and Riepert (2003) or Trotter and Gleser (1952).     

Estimation of stature and sex from scapular measurements by three-dimensional volume-rendering technique using in Chinese

In order to develop population – specific discriminant function equations and stature prediction equations for predicting sex and stature from measurements of the scapula in a contemporary Chinese, 414 individual 3D CT images were collected from participants undergoing routine examination. Sex differences for the variables were tested by Student’s t-test. Fisher’s method has been followed for discriminant analysis. Regression analysis was applied to match the six linear parameters against stature. The stepwise analysis of all measurements yielded a sex classification accuracy rate of 86.7% and a sex bias of 3.1%. All the classification accuracy rates of the univariate discriminant function analyses are of more than 80%. For stature estimation, the accuracy of stature prediction ranged from 5.252 to 7.210 cm for male, from 4.630 to 6.484 cm for female, respectively. This paper provides indications that the scapula is an important bone for sex diagnosis and it could be effectively used as alternatives in forensic cases. Furthermore, the equations presented for stature estimation in this study should be used as alternatives in forensic cases when long bones were unavailable for stature estimation.     

Sex estimation from foramen magnum parameters in adult Turkish population: A computed tomography study

Identification of skeletal relics is crucial for medicolegal purposes. Sex estimation is one of the critical parts providing the identification of skeletal relics. In forensic practice, sex estimation requires multidisciplinary studies of such as forensic medicine, anatomy, dentistry and radiology. Recently, radiological studies on this subject have been increasing with the developing technology. The objective of this study is to examine the usage of radiological dimensions of foramen magnum for sex estimation in human skulls by developing discriminant functions in Turkish population. We analyzed 600 (300 males and 300 females) Computerized Tomography (CT) images of Turkish individuals aged between 21 and 50. Four measurements were obtained from CT images. All measurements in males were significantly greater than in females, and they provided the higher sex classification accuracy. The area of the foramen magnum calculated by Radinsky's formula was the best measurement for sex estimation with a 75% accuracy rate. In conclusion, the CT images of foramen magnum show sexual dimorphism in our population. To use population specific data would be the most appropriate approach for sex estimation.     

Deletion of amelogenin Y-locus in forensics: Literature revision and description of a novel method for sex confirmation

Today, the molecular technique routinely for sex determination in forensics is based the detection of length variations in the X–Y homologous amelogenin gene (AMELX and AMELY).In humans, the amelogenin gene is a single-copy gene located on Xp22.1–Xp22.3 and Yp11.2; the simultaneous detection of the X and Y alleles using polymerase chain reaction (PCR) can lead to gender determination.Several studies have shown that normal males may be typed as females with this test: AMELY deletions may result in no product of amplification and normal males being typed as female as a result of the test (negative male).Considering the consequences of the result obtained using only the amelogenin marker, and the related potential difficulties in interpreting the results, the gender misinterpretation may be troublesome in clinical practice and in forensic casework.In this article, beginning with a review of the incidence of gender-testing failures among different populations, and with the different strategies proposed in the literature in case of doubt regarding the presence of deleted AMEL in the DNA profile, we propose a method for the identification of samples with deleted AMEL that can be applied, as an additional assay, in case of doubt regarding PCR results of sex determination.     

Identifying sexual dimorphism in a paediatric South Indian population using stepwise discriminant function analysis

Anthropological research relies on skeletal and dental remains for the identification of species. Sexual dimorphism is the systematic difference in form between males and females of the same species. This study is designed to compute a new formula for sex determination using discriminant function analysis in the deciduous crown dimensions of a paediatric population of South Indian origin and to check its accuracy. The sample consisted of 93 females and 90 males of South Indian origin aged between 5 and 13 years. Alginate impressions of the upper dental arch were made and casts were poured immediately. A digital vernier calliper was used to obtain measurements. Teeth considered for measurement were deciduous maxillary canines and molars. Our study is a maiden attempt in considering diagonal measurements along with mesiodistal (MD) and buccolingual (BL) dimensions as predictor variables for sex determination. Statistical analysis was performed using the Statistical Package for the Social Science version 17.0 software. By using the Student t-test, the different predictor variables of teeth selected between male and females were found to be significant (p < 0.05). Highly significant sexual dimorphism was found in the mean MD dimension of maxillary right canine and right and left first molar, BL dimension of right first molar, distobuccal–mesiolingual of right and left first molar and right second molar and mesiobuccal–distolingual of right second molar. The percentage of sexual dimorphism in MD dimensions revealed that the right upper first molar was the most dimorphic tooth and the upper first molar of the left side was the least dimorphic of the six teeth studied. The present study found the level of sexual dimorphism in the deciduous crown dimensions of a selected group of South Indian population, which is sufficiently large to determine sex with an accuracy of 87.2–88% by discriminant function analysis. Hence the formula derived from the present study could be of some value in sex determination of paediatric populations of South Indian origin.