Preliminary evaluation of palmar tri-radii-related measurements for sex estimation in an Arabian Gulf population sample

Abstract

Abstract This cross-sectional study assessed the utility of the distance between palmar tri-radii for sex estimation in an Arabian Gulf population. We enrolled 125 citizens of the Arabian Gulf residing in Alexandria Governorate, Egypt, aged 18–30 years. The palmprints were obtained using fingerprint ink strips. Software (AutoCAD 2025) was used to analyze the 600 dots per inch (dpi)-scanned images of the inked palmprints. We investigated five palmar tri-radii present at the base of the fingers (a, b, c, d) and axial tri-radius ‘t’ situated near the base of the fourth metacarpal. Four distances were measured, including the a-t, b-t, c-t, and d-t distances. Combined abcd-t distance was calculated for each palmprint. With excellent intra- and interobserver agreement, the measured variables exhibited significant sexual dimorphism, with males having larger values. Sex could be predicted from individual measurements, with modest performance. The most significant sex-predictive model incorporated bilateral palmprint measurements: log-odds of being male =-7.710 + 1.074 × (Right d-t) − 0.946 × (Right b-t) + 0.774× (Left a-t) + 0.590 × (Left c-t) − 0.334 × (Left d-t). The model achieved 82.7% sensitivity and an area under the curve of 76.2%. The palmar tri-radii-related measurements could guide sex estimation, alongside other evidence.