Estimation of Sex

The study of human skeletal remains from historic contexts is uniquely positioned to explore inequality over time by linking the underlying sociocultural factors that enforce marginalization with lived experiences and health outcomes. We analyzed mortality rates among historic individuals of low socioeconomic status from a documented human skeletal collection, to examine how culture and identity become biologically embodied. Because pre-existing health conditions affect mortality risk, we examined whether individuals with short stature experienced earlier mortality. Kaplan-Meier analyses and log rank tests indicated significant differences in survivorship over time and among social race groups, indicating that African American individuals showed significantly higher mortality, but no sex differences were observed within population groups. Logistic regressions tested for the effects of age-at-death, combined sex and population group, and birthdate on the outcome of bone length. Age and birthdate were not significant, suggesting no relationship between short stature and age-at-death, which also did not change over time. However, odds ratios indicated fewer African Americans were surviving up to adulthood. While many individuals in the collection likely suffered some poverty and marginalization, survivorship was significantly worse for African Americans. The likely effects of systematic racism resulting in further socioeconomic marginalization significantly affected the health of the African American community.

Adult sex estimation is one of the first and most important steps in forensic examination. While dealing with disturbed burials, the most dimorphic anatomic areas of the skeleton (such as the coxae, the skull and the head of femur and humerus) may be deteriorated or fragmented. In contrast, the minimum supero-inferior femoral neck diameter (SID) is generally much better preserved. The aim of the present research is to identify the discriminatory potential of SID for sex estimation and to test different formulae and mathematical procedures currently available in the forensic literature, on a sample of 295 contemporary individuals from the 21st Century Identified Skeletal Collection (University of Coimbra, Portugal), in order to identify its relevance for application in Portuguese forensic cases. Results showed that SID is a dimorphic variable, with high frequencies and probabilities of cases correctly estimated (0.82 and 0.83, respectively); statistically significant differences between females and males, and a high association between the metrics and sex, were identified. Posterior probabilities allow reliable estimations for all the measurements, excepting those between 31.0 and 31.5 mm, and the procedures that show the highest accuracy are those proposed by Seidemann et al. (1998), Curate et al. (2016), and Luna et al.(2021). Adult sex estimation from in a contemporary osteological sample from Buenos Aires, Argentina, with frequencies and probabilities between 0.82 and 0.83 for both sexes. The validation procedures implemented in this study highlight both the need to test quantitative models generated from diverse contemporary human populations, and the value of SID for obtaining reliable adult sex estimates, as they improve the quality of the biological profiles obtained in forensic contexts. Key points • Supero-inferior femoral neck diameter (SID) is relevant as a sex predictor due to its high preservation and dimorphic expression, especially in contexts of high fragmentation and commingling. • The study validated the existing functions of SID by calculating the frequencies of correct estimations for males, females, and both sexes. • The Bayesian approach yielded the best results, as posterior probabilities offered reliable estimations for almost all the measurements. • The study highlighted that SID showed sexual dimorphism in this population.

Stature estimation from skeletal remains is crucial in forensic anthropology. This study aimed to develop population-specific equations for stature estimation using ulna and radius measurements in a Northeastern Thai population, a region known for its ethnic diversity. A total of 400 ulnae and 400 radii (200 of each bone from each sex) were analyzed from dry bone specimens. The study objectives were to: (1) develop and validate regression equations for stature estimation, (2) investigate sex differences in the relationship between forearm bone lengths and stature, and (3) compare the accuracy of these equations with existing formulae for other populations. Results showed significant sexual dimorphism in stature and bone lengths. The mean stature was 164.93 ± 6.54 cm for males and 156.21 ± 5.81 cm for females (p < 0.05). Positive correlations were observed between bone lengths and stature, with stronger correlations in males (ulna: r = 0.670; radius: r = 0.663) compared to females (ulna: r = 0.402; radius: r = 0.393). Regression equations for the pooled sample yielded coefficients of determination (r²) of 0.516 for ulna and 0.509 for radius. Sex-specific equations demonstrated higher accuracy, particularly for males. The standard error of estimate ranged from 4.87 cm to 5.35 cm across all equations. These findings suggest that ulna and radius lengths are reliable predictors of stature in the Northeastern Thai population, with sex-specific equations offering improved accuracy. This study contributes to the development of population-specific standards in forensic anthropology and highlights the importance of considering sexual dimorphism in stature estimation. The results have significant implications for forensic investigations and archaeological studies in the region.

General introduction to the cranial base 1 Description of measurement techniques of the cranial base 3 Overview of cranial base growth Growth changes in cranial base flexion Evolution of cranial base flexion Inter-population variation in the cranial base of modern humans Aims of the present study CHAPTER 2: MATERIALS AND METHODS 43 Samples Methods CHAPTER 3: RESULTS AND DISCUSSION 85 Conclusion of cranial base angles Results of craniofacial angles Conclusion of craniofacial angles Summary of results for the dimensions of the cranial base and facial skeleton Conclusion of dimensions Correlations between the angles of cranial base flexion, craniofacial angles and dimensions Multivariate Statistical Analysis Conclusion of correlations and multivariate analyses Individual variation Modal faces-Z score comparison Comparison of modal face to the average

An automatic method for the detection of craniometric points in video based skull images is presented. This method assumes that skull images are in frontal view and erect posture of the head. An acquisition protocol is described, that facilitates the segmentation process. Although the proposed method uses simple algorithms of the image processing theory, it produces good results for undamaged skulls and is potentially very useful in the craniofacial identification process.

A critical component of the biological profile is sex estimation. Methods commonly used for sex estimation in adults do not work well for juveniles. Population‐specific studies have used cephalometrics to estimate juvenile sex with 80–90% accuracy. Our study attempts to estimate sex in individuals less than 18 years of age using a sample of 1618 lateral cephalograms incorporating all three Angle Class occlusions as well as population diversity. For the sample as a whole, 10 skeletal cephalometrics were found to have significant differences between the sexes. Males and females classify correctly about 50% of the time. Dividing the sample by age groups and race/ethnicity improves results for older age groups and Native Americans, Hispanics, and Asian Americans. Our results indicate that cephalometrics are not useful in determining sex of unidentified juveniles when age and race are not known.

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In forensic investigations of unknown skeletal remains, a biological profile is used to narrow the pool of potential matches in the missing person's database; one of the important components of that profile is the accurate estimation of skeletal sex. The current study involves the morphometric quantification of cranial sexual dimorphism in a Canadian population for the specific purpose of developing predictive models for the estimation of sex. The main aim of this study is, therefore, to quantify the accuracy methods of said existing sex estimation models as applied to a Canadian population and thereafter devise population-specific standards. The current study represents the retrospective analysis of 400 (190 female, 210 male) multiple detector computed tomography (MDCT) scans collected from the Sunnybrook Health Sciences Centre in Toronto, Ontario. Preliminary results indicate that current methods of cranial skeletal sex estimation illicit unacceptable classification accuracy rates when applied to this sample.

The use of 3D digital imaging methods has increased within biological anthropology and medical research. Although digital renderings can be easily shared by researchers or used for student learning modules in osteology, limitations to using 3D models exist, requiring institutions of higher learning to invest in real bones or casts of human skeletal remains for labs. Here, we examine whether 3D digital models are viable proxies for real bones by testing the reliability of scoring sexually dimorphic traits of the human skull, a method commonly used by North American skeletal biologists. Forty‐five crania from Peruvian archaeological sites were used to score four sexually dimorphic cranial traits. These morphological traits were scored by one student learning osteology and an experienced researcher using the actual crania and 3D models of the same individuals. Statistical tests of rater agreement and strength of the agreement were conducted.Results showed lower agreement between the ac...

Sex estimation remains one of the most important steps in a forensic anthropology context, especially when dealing with deteriorated or fragmented skeletal remains. In this respect, the need for the permanent actualisation of study database, as well of the skeletal remains is obvious. Therefore, besides classical skeletal collections an important amount of data can be obtained from computed imaging of the skeletal system, namely CT scans. The CT scans have the advantage of being virtually unlimited in number, not having any interference with secular trends, individuals being of known age and sex as well as increase in accessibility and applicability of data, for subsequent statistical and complex analysis (for instance, geometric morphometric). In the following review, we have gathered and compared some of the most significant studies in the field of physical and forensic anthropology focusing on sexual dimorphism on the skull, both on skeletal collections and CT scans. The results of the studies were similar in terms of sexing accuracy, thus allowing us to conclude that using CT scans in forensic anthropology is a viable and sometimes better option than skeletal collections, in term of data acquisition.

Purpose: The aim of this study is to evaluate the potential of craniofacial dimensions in estimating sex in a sample population in Kaduna State, Nigeria. Materials and Methods: This is a retrospective study of normal CT scan images of 399 Crania (comprising 236 males and 163 females) of age range 18–95 years that came for CT scans for the diagnostic purpose at the National Ear Care Centre, Kaduna between the years of 2017–2019. The images were randomly taken at the archives of the Radiology Department of the institute on an axial plane. The five craniofacial dimensions were measured directly from the computer screen using Vitrea CT Software. Results: Maximum cranial width (13.49±0.57 cm), maximum cranial length (18.11±0.74 cm), and bizygomatic length (12.64±0.58 cm) of males were significantly greater than in females (13.35±0.49 cm), (17.82±0.66 cm) and (12.22±0.59 cm) respectively. The bizygomatic length on the receiver operating characteristic curve (Area under the curve = 0.711),...