Population-specific sexual dimorphism in phalanges: development of forensic models using radiographs in the contemporary Malaysian population

Sex estimation is critical for the identification of individuals in forensic anthropology. Most existing forensic models for sex estimation have been developed using Western or non-Malaysian populations. Although pelvis and skulls are highly dimorphic, these bones may be missing and damaged for analysis. Therefore, alternative skeletal elements, such as phalanges, are being studied, focusing on the Malaysian population, aiming to develop a population-specific model for sex determination using phalangeal dimensions from X-ray images. A total of 218 X-ray images of appendicular skeletons of adult Malaysians (male = 105; female = 113) were obtained. Measurements of the proximal, middle, and distal phalanges were taken. Measurements were analysed using basic descriptive statistics and discriminant function analyses employing jackknife validations of classification results. The results showed significant sexual dimorphism when combining variables of the phalanges, achieving a maximum of 81.8% in classification accuracy with an associated sex bias of 0.59%. Males exhibit more robust skeletal features compared with females. This study demonstrates that radiographic measurements of the phalanges can serve as a reliable and accessible alternative for sex estimation in forensic contexts. The establishment of Malaysian-specific standards enhances the accuracy and applicability of forensic anthropology methods within the region.