Integrating Nasal Anthropometry with Multivariate Analyses to Examine Forensic Population Differentiation Between Malaysian and Indonesian Adults

Background/Objectives: Nasal morphology is an important craniofacial feature in forensic anthropology for examining population-level variation and informing biological profiling in living individuals. Despite genetic, historical, and cultural similarities between Malaysian and Indonesian populations, population-specific nasal anthropometric data remain limited. This study integrates nasal anthropometry with multivariate analytical approaches to examine population- and sex-related variation in nasal morphology among Malaysian and Indonesian adults. Methods: A cross-sectional anthropometric study was conducted among Malaysian and Indonesian adults. Nasal breadth and nasal height were measured using standardised techniques, and the nasal index was calculated. Univariate analyses were performed to assess population- and sex-related differences. Multivariate analyses, including principal component analysis (PCA), hierarchical cluster analysis (HCA), and partial least squares (PLS), were applied to eleven nasal parameters and the nasal index to evaluate patterns of population differentiation. Results: Malaysian participants predominantly exhibited leptorrhine nasal types, whereas mesorrhine nasal types were more prevalent among Indonesian participants. Significant differences were observed in nasal height and nasal index between populations, while nasal breadth did not differ significantly. Sex-related variation was evident, with males generally exhibiting larger nasal dimensions and higher nasal indices than females. Multivariate analyses demonstrated clear population separation, with modelling indicating that population group contributed more strongly to morphological differentiation than sex. Conclusions: The findings provide population-specific soft-tissue nasal data for Malaysian and Indonesian groups and support the use of multivariate analytical frameworks in forensic anthropological research.