Background: Sex estimation is a fundamental component of forensic anthropological analysis because establishing the probable biological sex of unidentified remains substantially narrows the pool of possible identities. The cranium is particularly valuable because of its durability and the presence of numerous sexually dimorphic features. Cranial vault morphology can be assessed using traditional osteometric techniques, radiographic methods, computed tomography (CT), three-dimensional reconstruction and increasingly sophisticated computational approaches.

Objective: This review examines the development and current application of cranial vault morphometry for forensic sex estimation, with particular emphasis on frontal, parietal and occipital cranial chords, three-dimensional computed tomography, geometric morphometrics, discriminant analysis, machine learning and population-specific standards.

Methods: A critical narrative review of published literature was undertaken using peer-reviewed literature indexed in PubMed and other major scholarly databases. Priority was given to original research, systematic and scoping reviews, and contemporary CTbased investigations published predominantly between 2018 and 2026. Earlier landmark studies were retained where necessary to explain the development of cranial morphometric methods.

Findings: Cranial vault dimensions demonstrate measurable sexual dimorphism in many populations, with males generally exhibiting larger cranial dimensions than females. However, the magnitude of dimorphism varies according to anatomical region, population, age, ancestry, measurement technique and analytical approach. Traditional cranial chords provide simple and reproducible measurements, but their diagnostic performance is generally enhanced when multiple variables are combined. Three-dimensional CT and geometric morphometric techniques permit assessment of complex cranial shape and reduce some limitations associated with conventional two-dimensional measurements. Recent studies demonstrate that multivariate discriminant models can achieve high classification accuracy, while machine-learning approaches increasingly permit automated analysis of three-dimensional cranial morphology. Nevertheless, population specificity, external validation, measurement standardization and algorithmic bias remain important concerns.

Conclusion: Cranial vault morphometry remains an important component of forensic sex estimation. Frontal, parietal and occipital measurements can provide useful population-specific information, but no single measurement should be regarded as universally diagnostic. The future of cranial sex estimation lies in integrating standardized CT acquisition, three-dimensional morphometry, robust statistical modelling and independently validated computational approaches. For Nigeria and other African populations, development of large contemporary CT databases and regionally validated equations is particularly important.