Sex determination from calcaneus in Korean using discriminant analysis

Linear measurements and shape analysis in the calcaneus of selected dog breeds

The vast array of dog breeds showcases a remarkable diversity that extends to osteological differences. Exploring these morphological distinctions and establishing reference data for various dog breeds are essential steps in comprehending the evolutionary changes that dogs have undergone. In this study, we conducted linear measurements of the calcaneus and performed shape analyses on selected dog breeds to elucidate distinctive characteristics among them. X-ray images of the calcaneus from six different dog breeds-Maltese Terrier, Toy Poodle, Pomeranian, Cavalier King Charles Spaniel, French Bulldog and Golden Retriever-were utilized for this investigation. Radiological images were obtained from a medio-lateral exposure, positioned 30 cm away from the x-ray device. From these images, four linear length measurements and two angle values were extracted. Additionally, a 2D geometric morphometric analysis was conducted using 32 semi landmarks placed on the radiological images. Linear measurements were assessed using ANOVA, while principal component analysis was employed to examine shape variations across all individuals. Shape differences between species were further elucidated through canonical variates analysis. The results revealed that the Golden Retriever exhibited the highest values for linear measurements, while the Pomeranian showed the lowest. Maltese Terriers displayed the highest dorsal calcaneal angle value. Notably, there were significant differences in calcaneal body length among all breeds, except for the Toy Poodle and Cavalier King Charles Spaniel. Moreover, Maltese Terriers exhibited statistically distinct angular measurements compared to other breeds. Principal component analysis unveiled that the first principal component explained 32.69% of the total variation, with the cranial edge of the calcaneal body being closer to the body in individuals with higher values. Shape variations also indicated that Golden Retrievers displayed a broader range of shapes compared to French Bulldogs, which exhibited a more conservative distribution. While there was no clear breed-specific distinction according to the first principal component, Cavalier King Charles Spaniels generally showed lower values. In canonical variates analysis, distinctions in calcaneal shape between species were apparent, with Golden Retrievers, Cavalier King Charles Spaniels and French Bulldogs displaying positive values for the first canonical variates. The highest Procrustes distance was observed between Maltese Terriers and Cavalier King Charles Spaniels. Notably, allometry was found to be statistically insignificant. This comprehensive study utilized both linear and geometric morphometric analyses based on x-ray images, yielding promising results. The integration of imaging systems in veterinary anatomy research presents numerous opportunities for studying animal welfare and health, utilizing various materials such as bones and cadavers. These advancements hold the potential for further enhancing our understanding of animal morphology and well-being.

A pilot study: Can calcaneus radiographic image be used to determine sex and breed in cats?

This study examined whether radiographic images measurements of the calcaneus in cats are determinative of sex and breed. For this purpose, radiographic images of 70 cats (37 male and 33 females) of different ages (from one to 18 years) and different breeds (41 mix-breed, 18 Scottish Fold and 11 British Shorthair cats) without orthopaedic problems were used. Right tarsal joint radiographs of these orthopaedically healthy cats were taken. Four linear measurements and two angle values of the calcaneus were obtained from the radiographic images. The MANOVA result showed that the most determining factor between the three groups was the greatest width (p value = 0.001). Calcaneal body length, calcaneal greatest length and calcaneal shortest depth were higher in mix-breed cats. Calcaneal tuber length was higher in Scottish Fold cats. The only statistically significant difference between Scottish Fold and British Shorthair was in the calcaneal tuber length (p value = 0.04). In the comparison made between the sexes regardless of species, the linear measurements in males were higher than in females. It was determined that these parameters are statistically significant in terms of sex differentiation in cats. Dorsal and plantar calcaneal angles are not sex determinants in cats. The effect of age on other measurements was analysed by correlation test. However, the effect of age on the measurements was not statistically significant. Mix-breed cats were examined in four groups according to their colour (grey, black-white, yellow, tri-colour). No statistically significant difference was found between calcaneal measurements of cats with different skin colour genotypes. In this study, calcaneus measurements were both determinative between breeds and sexes in cats.

A study on sex estimation by using machine learning algorithms with parameters obtained from computerized tomography images of the cranium

The aim of this study is to test whether sex prediction can be made by using machine learning algorithms (ML) with parameters taken from computerized tomography (CT) images of cranium and mandible skeleton which are known to be dimorphic. CT images of the cranium skeletons of 150 men and 150 women were included in the study. 25 parameters determined were tested with different ML algorithms. Accuracy (Acc), Specificity (Spe), Sensitivity (Sen), F1 score (F1), Matthews correlation coefficient (Mcc) values were included as performance criteria and Minitab 17 package program was used in descriptive statistical analyses. p ≤ 0.05 value was considered as statistically significant. In ML algorithms, the highest prediction was found with 0.90 Acc, 0.80 Mcc, 0.90 Spe, 0.90 Sen, 0.90 F1 values as a result of LR algorithms. As a result of confusion matrix, it was found that 27 of 30 males and 27 of 30 females were predicted correctly. Acc ratios of other MLs were found to be between 0.81 and 0.88. It has been concluded that the LR algorithm to be applied to the parameters obtained from CT images of the cranium skeleton will predict sex with high accuracy.

Sexing white 2D footprints using convolutional neural networks

Footprints are left, or obtained, in a variety of scenarios from crime scenes to anthropological investigations. Determining the sex of a footprint can be useful in screening such impressions and attempts have been made to do so using single or multi landmark distances, shape analyses and via the density of friction ridges. Here we explore the relative importance of different components in sexing two-dimensional foot impressions namely, size, shape and texture. We use a machine learning approach and compare this to more traditional methods of discrimination. Two datasets are used, a pilot data set collected from students at Bournemouth University (N = 196) and a larger data set collected by podiatrists at Sheffield NHS Teaching Hospital (N = 2677). Our convolutional neural network can sex a footprint with accuracy of around 90% on a test set of N = 267 footprint images using all image components, which is better than an expert can achieve. However, the quality of the impressions impacts on this success rate, but the results are promising and in time it may be possible to create an automated screening algorithm in which practitioners of whatever sort (medical or forensic) can obtain a first order sexing of a two-dimensional footprint.

Gender determination in adults using calcaneal diameters from lateral foot X-ray images in the Iranian population

Background: Using morphologic features of the bones is the basis of gender determination in anthropology and forensic medicine. In this study, we evaluated the calcaneus diameters for gender determination in the Iranian population.

Methods: This cross-sectional study was conducted on Iranians referring to Hazrat-e Rasool Hospital’s radiology ward for plain lateral X-ray of the foot. Lateral foot X-rays from 100 men and 100 women were gathered and evaluated for calcaneal indexes. These patients aged between 18 and 80 years old who did not suffer major trauma to the calcaneus bone were recruited. Using a picture archiving and communication system (PACS), four variables were calculated for each X-ray graph: Maximum anterior-posterior length of the calcaneus (MAXL), Maximum height of the bone (MAXH), Height of the cuboid facet (CFH) and Height the calcaneal body (BH). Cut off points for each index were calculated using the area under curve (AUC) in ROC curves.

Results: Lateral foot X-rays from 100 men and 100 women were gathered and evaluated for calcaneal indexes. The means of the four indexes were compared between the sexes which showed all four means are significantly different p value <0.001. AUC for MAXL in differentiating the genders was 0.824, which showed 86.8 as the cut off with a sensitivity of 80% and specificity of 69.0%. Cut off point for MAXH was set at 59.8 with sensitivity and specificity of 78.0% and 60.0%, respectively. For BH, 49.5 was set as the cut off point with a sensitivity of 79.0% and specificity of 64.0%. The best cut off point for CFH was 27.8 with 76.0% sensitivity and 63.0% specificity.

Conclusion: It can be concluded that the calcaneal diameters are reliable criteria for sex determination. Although the cutoff points are different between various races and populations, it is evident that these diameters can be used for sex determination in general.

Morphometric analysis of the patterns of calcaneal facets for the talus in Serbian population

Literature describes different patterns of calcaneal facets for the talus in terms of whether some calcaneal facets are connected or separated from each other or completely absent. The aim of this study was to establish the patterns of calcaneal facets for the talus, to calculate their total area, and to analyse the data with respect to gender. The study involved 59 calcanei which were photographed. The patterns of calcaneal facets noted in this study were compared with the patterns from the literature. ImageJ program was used to measure different parameters on calcanei. The pattern 1 was the most commonly found in the study sample (45.76%), then the pattern 2 (40.68%), and finally the pattern 3 (13.56%). That order of frequencies is the same in both sexes. The patterns 1 and 2 have a larger contact surface for the talus in comparison to the pattern 3. Male bones have a larger contact surface for the talus than female bones. The sum of the pattern 1 and pattern 3 frequencies was high. Knowing the frequency of different patterns of calcaneal facets for the talus in a certain population is important for orthopaedic surgeons when performing foot osteotomy.

Anthropometry of the human calcaneus and orientation of the articular facet for the cuboid bone as a basis for anatomically correct positioning of osteosynthetic screws in fracture treatment

PURPOSE

Fractures of the calcaneus are reported most commonly in the tarsal region. Their incidence is highest among active people in productive age. As such, optimal treatment can have vast implications for patients. The study aimed to compare calcaneal proportions of the Czech population in the last centuries to present day, for a precise choice and positioning of the osteosynthetic material, and its safe implantation in the anterior part of the calcaneus. Furthermore, we describe the frequency of the calcaneocuboid joint involvement in calcaneal fractures.

METHODS

We obtained 69 macerated (dry) human calcanei from anatomical collections along with multiplanar reconstructions obtained from 43 serial CT scans from patients with injuries other than calcaneal fractures. Specimens were measured using a modified set of Bidmos et al. criteria (2006). Two groups (CT scans of macerated specimens and patients' CT scans) were statistically evaluated and compared with the help of an experienced statistician. Furthermore, scans of 80 surgically treated patients were retrospectively assessed for calcaneocuboid joint involvement.

RESULTS

The median tilt of the calcaneocuboid joint in the transverse plane was 67° in the anatomical specimens and 72° in the multiplanar reconstructed CT scans taken from patients with intact tarsal regions. These results suggest that the length of screws should be ideally in the range between 21.3 and 25mm. In 47.3% of the patients presenting with a fractured calcaneus, the calcaneocuboid joint was involved. There was a statistically significant difference in most of the variables observed between the two groups.

CONCLUSION

As the calcaneocuboid joint involvement appears to be present in up to 50% of cases, adequate care should be taken. To maximize the biomechanical properties of the construct and to minimize the risks, our findings suggest the screws should be at an inner tilt of 68-74° from the lateral calcaneal wall and be of 23.5-26.2mm length. However, due to differences between the two groups and the small sample size, further investigation is needed.

A trial on artificial neural networks in predicting sex through bone length measurements on the first and fifth phalanges and metatarsals

BACKGROUND

Predicting sex is an important problem in forensic medicine. The femur, patella, mandible and calcaneus bones are frequently used in predicting sex. In our study, we aimed to use the artificial neural network (ANN) technique to predict sex by measuring the values of the phalanges of the first and fifth toes and the first and fifth metatarsal bones.

METHOD

All bone measurements were conducted on the direct X-ray images of 176 males and 178 females in the age range of 24-60 years. The multilayer perceptron classifier (MLPC) input layer included parameters on the bone length measurements of phalanx proximalis I, phalanx distalis I, metatarsal I, phalanx proximalis V, phalanx medialis V, phalanx distalis V and metatarsal V. The output layer contained two neurons to define the male and female sexes. The present study used an MLPC model that had two hidden layers, and the first and second hidden layers contained 14 and 7 nodes, respectively.

RESULTS

The model had an overall accuracy (Acc) of 0.95, specificity (Spe) of 0.97, sensitivity (Sen) of 0.95 and Matthews correlation coefficient (Mcc) of 0.92. While the sex prediction success of our proposed model was higher in women, the results were more specific in men and more sensitive in women (Acc^Male = 0.93, Acc^Female = 0.98, Sen^Male = 0.93, Spe^Male = 0.98, Sen^Female = 0.98 and Spe^Female = 0.93).

CONCLUSIONS

This study demonstrated that the ANN model for length measurements on small bones is a highly effective instrument for sex prediction.

Geometric morphometric analysis reveals age-related differences in the distal femur of Europeans

Background

Few studies have looked into age-related variations in femur shape. We hypothesized that three-dimensional (3D) geometric morphometric analysis of the distal femur would reveal age-related differences. The purpose of this study was to show that differences in distal femur shape related to age could be identified, visualized, and quantified using three-dimensional (3D) geometric morphometric analysis.

Methods

Geometric morphometric analysis was carried out on CT scans of the distal femur of 256 subjects living in the south of France. Ten landmarks were defined on 3D reconstructions of the distal femur. Both traditional metric and geometric morphometric analyses were carried out on these bone reconstructions. These analyses were used to identify trends in bone shape in various age-based subgroups (<40, 40–60, >60).

Results

Only the average bone shape of the < 40-year subgroup was statistically different from that of the other two groups. When the population was divided into two subgroups using 40 years of age as a threshold, the subject's age was correctly assigned 80% of the time.

Discussion

Age-related differences are present in this bone segment. This reliable, accurate method could be used for virtual autopsy and to perform diachronic and interethnic comparisons. Moreover, this study provides updated morphometric data for a modern population in the south of France.

Conclusion

Manufacturers of knee replacement implants will have to adapt their prosthesis models as the population evolves over time.

Three-dimensional geometric morphometric analysis reveals ethnic dimorphism in the shape of the femur

Background

Ethnic dimorphism in the distal femur has never been studied in a three-dimensional analysis focused on shape instead of size. Yet, this dimorphism has direct implications in orthopedic surgery and in anthropology. The goal of this study was to show that differences in distal femur shape related to ethnic dimorphism could be identified, visualized, and quantified using 3D geometric morphometric analysis.

Methods

CT scans of the distal femur were taken from 482 patients who were free of any bone-related pathology: 240 patients were European (E) and 242 were Asian (A). Ten osteometric landmarks based on standard bone landmarks used in anthropometry were placed on these scans. Geometric morphometric analysis, principal component analysis (PCA), canonical variates analysis (CVA), and other discriminant analyses (Goodall’s F-test and Mahalanobis distance) were performed. A cross-validation analysis was carried out to determine the percentage of cases in which the ethnicity was correctly estimated.

Results

The shape of the E and A distal femur differed significantly (Goodall’s F = 94.43, P < 0.001 and Mahalanobis D2 distance = 1.85, P < 0.001). PCA identified a difference in distal femur shape between A and E. The CVA revealed that correct ethnicity was assigned in 82% of cases and the cross-validation revealed a 75% rate of correct ethnic group estimation.

Conclusion

The distal femur exhibits ethnic dimorphism. 3D geometric morphometric analysis made it possible to demonstrate these differences. The large number of subjects studied has helped modernize the references for certain bone measurements, with direct implication for orthopedic surgery and anthropology.

Sexual dimorphism of the calcaneus in contemporary Cretans

During the past decade, several studies have been carried out using the calcaneus bone for sex estimation. This paper collected data using ten variables for metric characteristics of the calcaneus of 144 modern Cretans and examined their correlation with known sex. Secondly, the formulae developed by Peckmann et al. (2015) for modern Athenians was put to the test in order to investigate if it could be applied to this modern Cretan sample as well. Results showed a high correlation between the calcaneus metrics and the known sex of the individuals, however the formulae for Athenians do not seem to be suitable for the Cretans due to the high sex bias reported in this study. Thus, new standards were created for sex estimation from the calacanei in our sample. Bilateral asymmetry was noted in the majority of cases, thus formulae were developed for left, right and mean values. Maximum width (MAXW) was the variable that performed the best in the Cretan sample. Overall, the cross-validated accuracies for univariate and multivariate equations reached 84.2% with males most often correctly identified. The calcaneus was proved to be useful for sex estimation in this modern Cretan population. Further work will explore the suitability of the produced standards for other regions of mainland Greece and islands.

Determination of sex from various hand dimensions of Koreans

In the case of disasters or crime scenes, forensic anthropometric methods have been utilized as a reliable way to quickly confirm the identification of victims using only a few parts of the body. A total of 321 measurement data (from 167 males and 154 females) were analyzed to investigate the suitability of detailed hand dimensions as discriminators of sex. A total of 29 variables including length, breadth, thickness, and circumference of fingers, palm, and wrist were measured. The obtained data were analyzed using descriptive statistics and t-test. The accuracy of sex indication from the hand dimensions data was found using discriminant analysis. The age effect and interaction effect according to age and sex on hand dimensions were analyzed by ANOVA. The prediction accuracy on a wide age range was also compared. According to the results, the maximum hand circumference showed the highest accuracy of 88.6% for predicting sex for males and 89.6% for females. Although the breadth, circumference, and thickness of hand parts generally showed higher accuracy than the lengths of hand parts in predicting the sex of the participant, the breadth and circumference of some finger joints showed a significant difference according to age and gender. Thus, the dimensions of hand parts which are not affected by age or gender, such as hand length, palm length, hand breadth, and maximum hand thickness, are recommended to be used first in sex determination for a wide age range group. The results suggest that the detailed hand dimensions can also be used to identify sex for better accuracy; however, the aging effects need to be considered in estimating aged suspects.

Sexual dimorphism of the mandible in a contemporary Chinese Han population

A present limitation of forensic anthropology practice in China is the lack of population-specific criteria on contemporary human skeletons. In this study, a sample of 203 maxillofacial Cone beam computed tomography (CBCT) images, including 96 male and 107 female cases (20-65 years old), was analyzed to explore mandible sexual dimorphism in a population of contemporary adult Han Chinese to investigate the potential use of the mandible as sex indicator. A three-dimensional image from mandible CBCT scans was reconstructed using the SimPlant Pro 11.40 software. Nine linear and two angular parameters were measured. Discriminant function analysis (DFA) and logistic regression analysis (LRA) were used to develop the mathematics models for sex determination. All of the linear measurements studied and one angular measurement were found to be sexually dimorphic, with the maximum mandibular length and bi-condylar breadth being the most dimorphic by univariate DFA and LRA respectively. The cross-validated sex allocation accuracies on multivariate were ranged from 84.2% (direct DFA), 83.5% (direct LRA), 83.3% (stepwise DFA) to 80.5% (stepwise LRA). In general, multivariate DFA yielded a higher accuracy and LRA obtained a lower sex bias, and therefore both DFA and LRA had their own advantages for sex determination by the mandible in this sample. These results suggest that the mandible expresses sexual dimorphism in the contemporary adult Han Chinese population, indicating an excellent sexual discriminatory ability. Cone beam computed tomography scanning can be used as alternative source for contemporary osteometric techniques.