Sex determination from human cranium 3D CT based evaluation in an Indian population.

Sexual dimorphism of the mandible in a contemporary Chinese Han population

The prognostic significance of a battery of clinical, laboratory, and histological indicators was assessed in relation to mortality risk in a 1-year study of 253 patients with alcoholic liver disease, of whom 51 died within such time. The relative risk associated with each abnormality was calculated. A number of abnormalities was found to be statistically associated with a higher risk of death. Among the clinical abnormalities, these were: collateral circulation, edema, ascites, encephalopathy, spider nevi, anorexia, and weakness. Among the laboratory tests, these were: albumin, bilirubin, hemoglobin, abnormal prothrombin time, and alkaline phosphatase. Two hundred and sixteen of these patients had liver biopsies in which the quantifiable abnormalities were scored. Among the histological findings, the alterations significantly related to mortality were necrosis, Mallory, and inflammation, while the presence of cirrhosis per se did not influence the mortality risk. The relative risk factors for mortality associated with the histological alterations were lower than those derived from clinical or laboratory measurements. The advantage of using only clinical and laboratory items to derive a global, quantitative expression of severity is discussed. The relative mortality risks provided a means of calculating a "unit of severity" for each clinical and laboratory abnormality. A combined clinical and laboratory index (CCLI) results when these mortality-risk units are added. Such a combined index had a quasi-linear relationship with the risk of mortality for the complete population. This method compared well with severity scores derived from computerized, linear step-wise discriminant function (SDF) analysis and from a logistic regression (LR) analysis. The factors chosen to have independent prognostic significance by the SDF analysis were: encephalopathy, albumin, prothrombin time, and hemoglobin, while only encephalopathy, albumin, and hemoglobin were chosen by the LR analysis. Within a range of values, LR can provide a good discrimination in relation to mortality, similar to that observed for the CCLI in its complete range. However, there are some advantages to the CCLI method vs. the LR or SDF analyses. The CCLI is less susceptible to being unduly influenced by a nonspecific effect of treatment on the items chosen than the SDF and LR analyses, as the CCLI contains a large number of factors. Obtaining a single-severity score such as the CCLI is of value in: (a) assessing the effectiveness of treatment modalities; (b) analyzing the success of randomization; (c) separating cohorts of different severity, and (d) comparing new liver tests, histological abnormalities, or specific biological events with the severity of alcoholic liver disease.

Assessment of craniometric traits in South Indian dry skulls for sex determination

Morphometric sex determination from various sternal widths of Northwest Indian sternums collected from autopsy cadavers: A comparison of sexing methods

Evaluating the patella bone for sex estimation in Northwest Indian subjects: A radiological study

Forensic anthropology involves diverse applications of anthropological knowledge to medico-legal problems like human identification based on sex determination, age estimation, stature reconstruction and deciphering ancestry of unknown living individuals or skeletal remains. Sex can be determined by using different body parts such as extremities (legs and arms) parameters, head, face, clavicle, and others parameters. In present cross-sectional study, cephalometric dimensions of 800 Ladakhi subjects (431 males and 369 females) of Purigpas and Brokpas ancestry were taken. Descriptive statistics of cumulative cephalometrics in two sexes revealed that all the measurements were significantly larger in males than the females (p<0.001). Statistically significant sex differences were found in the various anthropometric, cephalometric and morphological features of Brokpas and Purigpas of Kargil (Ladakh, UT). Univariate discriminant function analysis found head length as the best cephalofacial variable to estimate sex of 73.4% individuals; followed by physiognomic facial length to estimate sex of 71% subjects. From multivariate discriminant function analysis, the physiological facial length, head length, nasal breadth, head circumference, nasal height, bizygomatic breadth, length of right ear and left ear breadth were selected as the best variables to correctly classify sex of 83.8% individuals to their category (81.9% males and 85.9% females). The present study results are the only cephalometric standards which have been suggested for Purigpas and Brokpas of Ladakh (Jammu and Kashmir) which can be used for medico-legal sex determination of unknown individuals of studied population.

Accurate determination of sex from the skeletal remains of unidentified individuals is challenging in forensic practice. The bone standards for sex determination are population and generation specific. The present study investigated the potential utility of the craniofacial bones as an indicator of sex in a contemporary sample of the central Chinese population. A total of 171 adults (75 male, 96 female) of known age and sex underwent cone beam computed tomography (CBCT). A three-dimensional image from skull CBCT was reconstructed using specialized software (SimPlant Pro, version 11.04). Eleven linear measurements were selected to be measured, nine of which were sexually dimorphic. Discriminant function analysis (DFA) and logistic regression analysis (LRA) were used to develop mathematical models for sex determination. The equations of various variable combinations achieved classification rates of 83.6% in DFA and 84.8% in LRA, with cross-validation rates >80%. Results of the present study indicated that the accuracy of the craniofacial bones to determine sex could reach >80%, and bizygomatic breadth was the most sexually dimorphic variable among the craniofacial bones.Key pointsSexual dimorphism of 11 linear dimensions of the craniofacial bones of a central Chinese population were studied.The accuracy of the craniofacial bones in determining sex was as high as 84.8%.The craniofacial bones were useful for determining sex in a sample of the central Chinese population.

The aim of the study is to assess the sex differences in size and shape of the foramen magnum, to develop discrim­inant functions based on the measurements of the foramen magnum and to establish the most reliable variables for sex determination in Bulgarian adults. Computed tomography scans of the heads of 120 Bulgarian adults (52 males and 68 females) were used in the study. The segmentation of the skulls was performed with the software InVesalius. The length, breadth, and cir­cumference of the foramen were measured digitally based on the 3D coordinates of definite landmarks and semi­landmarks. The area of the foramen magnum was calculated using the Radinsky and Teixeria formulae, based on the dimensions of the foramen length and breadth. The shape of foramen magnum was classified as narrow, medium wide or wide on the basis of the breadth/length index values. The significance of the sex differences in the measurements and shape of foramen magnum was assessed by independent sample t-test and chi-square test. Univariate and multivariate discriminate function analyses were conducted. The leave-one-out classification method was used as a cross-validation procedure. The results demonstrated statistically significant sex differences in the size and shape of the foramen magnum. The area of the foramen magnum is the best discriminating parameter. Generally, the results from the univariate and multivariate discriminant function analysis showed that the measurements of the foramen magnum did not provide high predicting rates for sex estimation among the Bulgarian population. Acknowledgements: The study was supported by the Bulgarian National Science Fund, grant DN01/15-20.12.2016.

Logistic regression modeling and the number of events per variable: selection bias dominates

Biological profiling of unknown human remains is the foremost task required in forensic/medico-legal death investigations and sex determination of such remains is an important element of biological identity of an individual. In present study, 12 anthropometric measurements were recorded on 298 Uttarkashi individuals (150 males and 148 females) between age group of 18-25 years. Majority of measurements were found to have a significant degree of sexual dimorphism among them; being highest for cubit and thumb lengths and lowest for left palm and right foot lengths (p &gt;0.001). From Univariate discriminant function analysis, cubit length and left foot length were selected as the best variables to discriminate sex of about 80% (84% males and 76% females) 79% (84.7% males and 73.6% females) individuals, respectively. Similarly, 86% subjects could be classified to their correct sex category from all the lineal measurements (88.5% males and 87.2% females) or the hand measurements only (83.1% males and 84.6% females) from the multivariate discriminant function analysis. The results of present study can be considered an addendum to the existing population data for forensic anthropological literature.

Forensic odontological sex determination of Ajnala skeletal remains based on the statistical equations generated from the odontometrics of known teeth

Introduction: Sex determination is a critical step in the identification of individuals in forensic medicine. Cone beam computed tomography (CBCT) is an excellent tool for analyzing the volume of paranasal sinuses that can be used for sex determination. Aim: To measure and compare sexual dimorphism in the bizygomatic distance and the volumes of the maxillary and sphenoidal sinuses on CBCT images and evaluate their significance in sex determination. Materials and Methods: A retrospective study was conducted using 102 CBCT scans, which were analyzed using ITK-SNAP software to determine the volumes of the maxillary sinus and sphenoidal sinuses. The bizygomatic width was measured in the axial section. The differences in the volumes of the maxillary and sphenoidal sinuses and bizygomatic width were assessed for their significance in sex determination. The study population was divided into male and female groups (51 males and 51 females). The age range was 20–75 years. Statistical analysis was conducted using independent t-tests and discriminant functional analysis. Results: Statistically significant differences were observed in bizygomatic width, right maxillary sinus volume, left sphenoidal sinus volume, total maxillary sinus volume, and total sphenoidal sinus volume (P &lt; 0.05). Conclusion: Adult paranasal sinus volumes and bizygomatic width analyzed using CBCT may be useful for sex determination in forensic investigations.

Background:Sex identification of unknown individuals is important in forensic sciences. At times when only skull remains are found and other means of identification fails, radiographs of frontal sinus can be used for identification. Frontal sinus morphology is unique to individual and can be used effectively in person identification; whereas its use in determining sexual dimorphism is limited.Aim:To determine sexual dimorphism among Indians by evaluating frontal sinus pattern using postero-anterior radiograph.Materials and Methods:The right and left areas, maximum height and width of frontal sinus were determined in 300 digital postero-anterior view radiographs obtained from 150 males and 150 females aged between 18-30 years. The measurements were carried out by transferring the image to Adobe® Photoshop® CS3 extended. Comparison of values were done using student's t-test and accuracy of sex determination was assessed through Logistic regression analysis.Results and Conclusions:One hundred and forty seven males and 142 females show presence of frontal sinus with seven individuals showing unilateral/bilateral absence of frontal sinuses. The mean values of the frontal sinus height, width and area are greater in males. Right frontal sinus is larger than the left sinus in both the sex. The mathematical model based on logistic regression analysis gives an average concordance index for sex determination of 64.6%. Thus, frontal sinus provides average accuracy in sex determination among Indian population. This may be due to its greater variation in morphology.

BackgroundSex estimation is the first stage in the identification of an individual in the forensic context, and can be carried out from bone structures like the mandible. The aim of this study was to estimate sex from metric analysis of the mandible in cone beam computed tomography images (CBCT) of adult Chilean individuals.MethodsSix mandibular measurements were analysed, five linear and one angular, in CBCT of adult Chilean individuals of both sexes. ROC Curve analysis was performed, with cut-off points, and of the overall model quality. Univariate discriminant function analysis was used to determine the accuracy of each measurement for sex estimation. Multivariate discriminant function analysis, both directly and by steps, was used to obtain the predictive value of the mandible including all the measurements.ResultsThe data included were 155 CBCT, 105 of females and 50 of males. The mandible presented great sexual dimorphism, with the mandibular ramus presenting greater predictive power than the mandibular body. When each mandibular measurement was analysed separately, the maximum height of the mandibular ramus presented the greatest predictive power (76.5%), while the mandibular angle was the least accurate parameter for sex estimation (58.1%). Direct method analysis presented 87.1% accuracy for sex identification of adult Chilean individuals, and joint analysis of maximum mandibular ramus height (MRH), corono-condylar distance and bigonial breadth presented 86.5% accuracy. In ROC Curve analysis the MRH was the variable with the greatest discriminating capacity (AUC = 0.833), MA was the only variable which presented no discriminating capacity (AUC = 0.386) and also presented low quality in model quality analysis.ConclusionMetric analysis of the mandible in CBCT images presents an acceptable accuracy for sex estimation in Chilean individuals, and its use for that purpose in forensic practice is recommended.

Context:Identification of sex from skeletal remains is one of the important forensic considerations. Discriminant function analysis is increasingly used to determine the sex from skeleton.Aims:To develop discriminant function to determine sex from mandible in a Central Indian population.Settings and Design:This was a prospective study done at the Department of Anatomy.Materials and Methods:The mandibles used in the present study were from the museum specimens. Only 82 adult mandibles (55 male and 27 female) that had been preserved were selected. Ten mandibular parameters were measured.Statistical Analysis Used:Statistical analysis was conducted using Statistical Package for Social Sciences (SPSS) for Windows, version 16. The level of statistical significance was set at P < 0.05.Results:Using stepwise discriminant function analysis, only six variables were selected as the best discriminant between sexes, with the projection length of corpus mandibulae being the most dimorphic. It was observed that sex classification accuracy of the discriminant functions ranged from 57.3 to 80.5% for the individual variables, 81.7% for the stepwise method, and 85.4% for the direct method.Conclusion:The results of the study show that mandibles can be used for determining sex and the results are comparable with other similar studies. The studied mandibular variables showed sexual dimorphism with an accuracy comparable with other skeletal remains, next to cranium and pelvis.