Sex determination using upper limb bones in Korean populations

A comprehensive morphometric analysis of crista galli for sex determination with a novel morphological classification on computed tomography images

PURPOSE

This study aimed to examine the morphometry of the crista galli (CG) on paranasal sinus computed tomography (PNCT) images to develop a new approach of morphological classification with objective radiological criteria and to investigate the relationship of morphometric and morphological characteristics with gender.

METHODS

The height, width, and length of the CG were measured on the PNCT images of 533 subjects (266 males, 267 females). Based on the dimensions and the presence of the cavitary component of the CG, the CG was classified into three morphological types. The success of CG dimensions and new morphological classification of CG in the determination of gender was evaluated with ROC and Paired Logistic Regression analyses.

RESULTS

The morphometric cutoff values of the height, width, and length of the CG for the estimation of gender were determined as 15.15, 3.45, and 13.25 mm, respectively. CG length (accuracy 83.7%) showed more successful classification rate on gender determination as compared to height (accuracy: 81.4%), and width (accuracy 81.2%) of the CG. The presence of ossified type CG accurately identified the male sex at a rate of 88.7%, and teardrop type CG determined female sex at a rate of 82.9%. Tubular type CG identified male sex correctly at the rate of 65.8%.

CONCLUSION

The height, length, and width measurements of CG on PNCT images and the new morphological types recommended in this study can be used in the determination of gender with high accuracy rates.

Tailored logistic regression models for sex estimation of unknown individuals using the published population data of the humeral epiphyses

This paper introduces a far-flung approach to formulate population independent models based on the humeral epiphyses as a supplementary tool for biological sex estimation of unknown partial remains. Resources for this study include the published summary statistics of 7 modern populations inhabited the continents of Africa, Asia, Europe, and South America. The regenerated humeral metric data (n = 1490) via truncation approach were modeled using logistic regression. Three fitted models were evaluated for applicability across populations on an independent test sample (n = 430). The experiment was assessed graphically and quantitatively using histogram of posterior probabilities and the classification table. The predictive power of the models was evaluated at the conventional (0.5) and high (0.95) posterior probability thresholds. It was found that the vertical humeral head model is insufficient for sex estimation especially in the European females due to different levels of interpopulation size variability. Interestingly, the distal biepicondylar breadth model showed overall better performance achieving the highest total and sex specific accuracies. Findings indicated that together, the epiphyseal measurements are capable of discriminating sex with overall accuracy of 90.2% which is raised up to 98.8% with 95% confidence of accurate estimates in more than 50% of the test sample. While evidences have been presented pointing to the biological and statistical meaningfulness of the humeral epiphyses model, the analysis allowed pinpointing the utility of the distal biepicondylar breadth model in sex diagnosis in transpopulation application settings. Additionally, few variables are needed to reach satisfactory sex prediction in a diverse sample.

Sex estimation from upper limb bones in a Thai population

Sex estimation from skeletal remains is an important practice for forensic human identification. The aims of this study were to assess sexual dimorphism and to develop discriminant function equations for sex estimation using 12 measurements of upper limb bones (humerus, ulna, and radius) in a Thai population. The sample consisted of 228 Thai skeletons (114 males and 114 females) from the Forensic Osteology Research Center, Chiang Mai University, Chiang Mai, Thailand. All skeletal length variables were measured according to the Standards for Data Collection from Human Skeletal Remains. The values of measurements were used to develop the sex estimation equations using univariate and multivariate discriminant function analyses. The results of sexual dimorphism showed that upper limb bone lengths of males were statistically significantly longer than those of females in all dimensions (P<0.05). For univariate discriminant function analysis, the results showed that the epicondylar breadth of the humerus, the physiological length of the ulna, and the antero-posterior diameter at the midshaft of the radius were the best indicators for sex estimation in the humerus, ulna, and radius, respectively. Moreover, the multivariate discriminant function equation using all variables of the ulna and radius was the best indicator for sex estimation. In conclusion, the discriminant function equations derived from upper limb bone measurements provided highly accurate sex estimation in Thai samples. Therefore, these equations using humerus, radius, and ulna measurements can be applied for sex estimation with good accuracy in Thais.

Odontometric sex discrimination in young Urhobo adults of South-South Nigeria

The spate of unidentified human remains as a result of kidnapping, killings, and so forth was the reason for this study. The purpose of this study was to measure the crown and cusps of each of the permanent maxillary first two molars to determine discriminant score and functions among Urhobo people of Nigeria. All Undergraduates of the Delta State University, Abraka, who are pure breeds Urhobo, form the study population. Three hundred and six subjects (171 males and 135 females), with mean age 22.88±3.34 years, participated in the study, which is based on the simple random sampling technique. All four crown widths and the four cusps of the maxillary first two molars were measured in millimeter, from a prepared study models of dental stone, and crown area, crown and cusps indices were calculated. The level of sexual dimorphism was also calculated for each parameter. Descriptive statistics was used to summarize the data while inferential statistics were used to ascertain significant sexual differences and to determine discriminant scores and functions. Statistical significance was fixed at P≤0.05. Crown and cusp dimensions of the first two permanent maxillary molars exhibited statistically significant sexual dimorphism. The highest percentage of sexual dimorphism was crown area of maxillary second molar (9.08%), followed by first molar (7.85%). Next, were metacone, paracone, disto-buccomesio-lingual, and mesio-buccodisto-lingual widths. The overall sex discriminatory precisions of the various parameters in the maxillary first two molars are good. The findings of this study are of relevance in forensic anthropology.

Sex determination using humeral dimensions in a sample from KwaZulu-Natal: an osteometric study

The morphological characteristics of the humeral bone has been investigated in recent times with studies showing varying degrees of sexual dimorphism. Osteologists and forensic scientists have shown that sex determination methods based on skeletal measurements are population specific, and these population-specific variations are present in many body dimensions. The present study aims to establish sex identification using osteometric standards for the humerus in a contemporary KwaZulu-Natal population. A total of 11 parameters were measured in a sample of n=211 humeri (males, 113; females, 98) from the osteological collection in the Discipline of Clinical Anatomy, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa. The difference in means for nearly all variables were found to be significantly higher in males compared to females (P<0.01) with the most effective single parameter for predicting sex being the vertical head diameter having an accuracy of 82.5%. Stepwise discriminant analysis increased the overall accuracy rate to 87.7% when all measurements were jointly applied. We conclude that the humerus is an important bone which can be reliably used for sex determination based on standard metric methods despite minor tribal or ancestral differences amongst an otherwise homogenous population.

Sex estimation of upper long bones by selected measurements in a Radom (Poland) population from the 18th and 19th centuries AD

Several studies have shown that sex estimation methods based on measurements of the skeleton are specific to populations. Metric traits of the upper long bones have been reported as reliable indicators of sex. This study was designed to determine whether the four long bones can be used for the sex estimation of an historical skeletal population from Radom (Poland). The material used consists of the bones of 169 adult individuals (including 103 males and 66 females) from the 18th and 19th centuries. Twelve measurements were recovered from clavicle, humerus, radius and ulna. The initial comparison of males and females indicated significant differences in all measurements (p < 0.0001). The accuracy of sex estimation ranged from 68% to 84%. The best predictor for sex estimation of all the measurements in Radom’s population was the maximum length of the radius (84%), and the ulna (83%), and the vertical diameter of the humeral head (83%). The Generalized Linear Model (GLM) detected the strongest significant relationship between referential sex and the vertical diameter of the humeral head (p < 0.0001), followed by the maximal length of the ulna (p = 0.0117). In other measurements of the upper long bones, GLM did not detect statistically significant differences.

Binary logistic regression analysis of hard palate dimensions for sexing human crania

Sex determination is the preliminary step in every forensic investigation and the hard palate assumes significance in cranial sexing in cases involving burns and explosions due to its resistant nature and secluded location. This study analyzes the sexing potential of incisive foramen to posterior nasal spine length, palatine process of maxilla length, horizontal plate of palatine bone length and transverse length between the greater palatine foramina. The study deviates from the conventional method of measuring the maxillo-alveolar length and breadth as the dimensions considered in this study are more heat resistant and useful in situations with damaged alveolar margins. The study involves 50 male and 50 female adult dry skulls of Indian ethnic group. The dimensions measured were statistically analyzed using Student's t test, binary logistic regression and receiver operating characteristic curve. It was observed that the incisive foramen to posterior nasal spine length is a definite sex marker with sex predictability of 87.2%. The palatine process of maxilla length with 66.8% sex predictability and the horizontal plate of palatine bone length with 71.9% sex predictability cannot be relied upon as definite sex markers. The transverse length between the greater palatine foramina is statistically insignificant in sexing crania (P=0.318). Considering a significant overlap of values in both the sexes the palatal dimensions singularly cannot be relied upon for sexing. Nevertheless, considering the high sex predictability of incisive foramen to posterior nasal spine length this dimension can definitely be used to supplement other sexing evidence available to precisely conclude the cranial sex.

Craniometric study for sex determination in a Thai population

Sex determination is an important step in biological identification from skeletal remains, especially in forensic circumstances. Many authors suggested that the morphological study was more subjective than the metric. There are various craniometric studies in different populations. They revealed that there was population-specific for the sex discriminant equation derived from each population. Thus, the present study aimed to evaluate sexual dimorphism and develop the discriminant function from 200 Thai skulls. Twenty-five standard cranial measurements were examined. The results revealed that males' cranium were statistically significant larger than females' in all measurements (P<0.05), except for minimum breadth of nasal bone. Sexual dimorphism index also expressed relatively high male/female ratio indicating great sexual dimorphism. The best practical equation for sex determination with six measurements (maximum cranial length, bizygomatic breadth, biauricular breadth, nasal height, biorbital breadth and right mastoid length) was derived from a stepwise discriminant method. This equation with 90.6% accuracy (91.1% in male and 90.0% in female) can provide valuable application utilizing in sex determination from skull in a Thai population.