Sex estimation is one of the primary aspects in determining the biological characteristics of an unknown adult skeleton. The variations between male and female skeletons can be attributed to a complex interplay of genetics, hormonal factors, culture, and environment. However, skeletal remains frequently found are often incomplete, with most sexually dimorphic bone like the pelvis and skull potentially absent. Hence, it is essential to conduct a comprehensive evaluation of multiple skeletal elements to attain a high degree of precision in sex estimation within forensic anthropology context. Ribs have been utilized in forensic anthropology for sex estimation since the 1980s, a comprehensive review of their sexual dimorphism is yet to be conducted. In this study, we examined various anthropological methods applied to ribs for sex estimation. Method: A systematic search was performed using PubMed, Science Direct, and Google Scholar from 2000 to 2020, retrieving a total of 10 articles that met the inclusive criteria. The search followed the main points outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: This systematic review provides a comprehensive summary of the analytical approaches employed to estimate sex using human ribs. Conclusion: The findings revealed that different part of human ribs can be reliably used for sex estimation via metric method.

Age estimation in adults is a complicated task because of various external factors occur concurrently with increasing age. The geometric morphometric method (GMM) is an approach that focuses on shape analysis and is widely recognized for its high reliability and reproducibility. The aim of this study was to explore the variation of cervical vertebrae among different age groups of the Malaysian population by GMM. Lateral skull radiographs of 432 subjects comprising four adult age groups; young adult age group (20–30 years old), early middle age group (31–40 years old), late middle age group (41–50 years old) and, elder adult age group (51–60 years old) were selected. Fifty-three 2-dimensional (2D) landmarks were applied to the digitalized radiographs by TPSDig2 (Version 2.31) software. Geometric morphometric analysis was performed by MorphoJ software. Results showed that the first three principal components (PC) contributed to 47.71 % of the cervical vertebrae variation and were shown in both lollipop and wireframe graphs. Procrustes ANOVA indicated that the shape was significantly different among different age groups. Canonical variate analysis revealed significant differences of both mahalanobis and procrustes distances among age groups with substantial individual overlap within groups. Discriminant function analysis (DFA) showed a correct classification rate for 61.5 % of cases respective to age groups. In conclusion, this study found significant differences in the shape of cervical vertebrae among different age groups of the Malaysian population using the GMM.

Background: Age estimation of unidentified human remains is an essential for establishing the biological profile of unidentified human remains. Previous studies have investigated the value linear measurements of the frontal sinus for age estimation while the value of two-dimensional (2D) geometric morphometric measurements have not been explored for this purpose. Objective: This study aims to evaluate the morphological variation of frontal sinus among adults Malaysian for age estimation using 2D geometric morphometric methods. Methods: Lateral skull radiographs of 453 adult Malaysians, comprising 151 young adults (20–39 years old), 150 middle-aged adults (40–59 years old) and 152 old adults (60–79 years old), were retrieved retrospectively. Eight 2D landmarks were applied to digitalized radiographs using TPSDig2 software. 2D geometric morphometric analysis was performed by MorphoJ software. Results: Procrustes ANOVA revealed no significant differences in shape and size (p-value > 0.05) of frontal sinus between the three age groups. However, Canonical Variate Analysis showed significant differences for Mahalanobis and Procrustes distances (p-value < 0.05) between young and old adult groups. Discriminant Function Analysis after cross-validation demonstrated an age classification accuracy of 53.5 %. Conclusion: The study suggests that 2D geometric morphometric analysis of the frontal sinus cannot be reliably used to estimate the age of an unknown Malaysian individual.

Sex determination is the crucial stage for developing a biological profile during the investigation of skeletal remains. An accurate determination of the sex of the unknown person is crucial by only a few bones or when multiple bones are missing or fractured. Thus, exploration of less commonly used bones like thoracic vertebrae is also required for the personal identification of an unknown individual.

Sex identification is essential for the establishment of an accurate biological profile from skeletal remains in forensic anthropology. Conventional method using calipers is time-consuming and associated with a high margin of error especially in the case of highly fragmented skeletal remains. Geometric morphometric method is an approach which utilizes qualitative and quantitative description of biological forms according to geometric definitions of their shape. This study aimed to determine sexual dimorphism of third cervical (C3) vertebra on the lateral cervical radiograph by geometric morphometric method. Lateral cervical radiographs of 432 samples comprising of 262 males and 170 females of known individuals were retrieved retrospectively. The samples were adult Malaysian population aged from 20 to 60 years old. Eleven 2-dimensional (2D) landmarks were applied on the digitalized radiographs by TPSDig2 (Version 2.31) software. Geometric morphometric analysis was performed by MorphoJ software. Procrustes ANOVA showed that centroid size and shape are significantly different with p<0.001. Discriminant function analysis (DFA) showed 70% classification accuracy, with identification accuracy of 70.6% for males and 70.0% for females. There were significant differences between sex in the height of vertebral body, length of the superior articular process as well as length of the superior part of spinous process of C3 (p<0.05; Independent t-test). In conclusion, sexual dimorphism demonstrated in the C3 vertebra confirms the utilization of 2D geometric morphometric as one of the methods for sex estimation. To the best of our knowledge, this is the first study to report such findings among Malaysian population.

Sexual identification is the most crucial step in the forensic anthropology field. Traditional morphometric techniques, involving caliper-based measurements, are often labor-intensive and time-consuming. In contrast, the geometric morphometric method (GMM) offers a more efficient approach, integrating qualitative and quantitative assessments of biological forms based on precise geometric characterizations of their shape. This study aimed to assess sexual dimorphism of the Atlas (C1) bone on lateral cervical radiographs using GMM. A cross-sectional design was employed, utilizinglateral cervical radiographs from a sample of 413 individuals, including 208 males and 205 females, age ranged between 35 and 45 years old. Six 2D landmarks were identified and marked on the digitalized radiographs using TPSDig2 (Version 2.31) software. GMM analysis conducted by MorphoJ software. Eight principal components (PC) accounted for 100 % of the shape variability produced. Procrustes ANOVA showed that centroid size and shape were significantly different between different sexes. Discriminant function analysis (DFA) revealed a correct classification rate for 87.9 % of cases, with an identification accuracy of 87.0 % for males and 88.8 % for females. There were significant differences among males and females in the height of the C1 vertebral body with p < 0.05 via independent t-test. In conclusion, there was a significant sexual dimorphism of the C1 vertebra by GMM, which could serve as an alternative method in physical anthropology and forensic medicine.