Impact of aging on fingerprint ridge density: Anthropometry and forensic implications in sex inference

The variation in the epidermal ridge's width between the sexes, during various growth stages, and among different populations has been previously assessed. However, the changes that occur with aging are barely known. The goal of this study was to analyse the degree of variation in epidermal ridge width due to aging. So that, fingerprint ridge density was estimated to establish their relationship with body and hand size changes that typically occur in adulthood. In this study, a sample of 213 adults of both sexes from a Spanish native population of different age ranges-18-30 years old ("junior" group) and 50-66 years old ("senior" group)-was used. Ridge density was assessed in three counting areas of the distal phalanx of each finger (radial, ulnar, and proximal). Height, weight, and a set of anthropometric measurements for both hands were also taken. Our results show that ridge density is higher in females than males throughout adulthood and decreases with aging in the radial and ulnar areas (as the hands widen) but not in the proximal region. Thus, a relationship between hand dimensions and ridge density was found. The data indicate that aging changes may conceal the recognized sex differences in ridge density, and so a better understanding of the topological variations in the epidermal ridge width throughout the life cycle and the factors involved would facilitate the interpretation of the differences between the sexes and different age groups.