Age, sex and positional variations in the human epidermal ridge breadth by multiple measurements on a cross-sectional sample of school-age children

Abstract

A number of studies have used the measurement of density of epidermal ridges on human fingerprints (or average epidermal ridge breadth if the value is expressed in reverse) as a metric to estimate the age of the originator of the imprint at the time of growth and sex at maturity. A methodologically unsolved question is how the number of ridges measured together within one segment (or the length of the line segment across which the ridges are counted) affects the results. In this study, we therefore investigated how the count of ridges measured together within one segment, as well as the count of averaged segments per subject, when averaged, affect the resulting values of mean epidermal ridge breadth. Moreover, we investigated how different regions on the human fingers and palms differ in this respect. Using a cross-sectional sample of 90 school children (45 girls and 45 boys, age range from 6 to 16 years)from South Moravia, we compared the differences in epidermal ridge breadth in 29 different hand regions, particularly in terms of the degree of age differences. The results show that different regions on the hand vary significantly in the effect of age which might have consequences for estimating age and sex based on these epidermal ridge breadth measurements. However,the ability to statistically distinguish age or sex groups is affected by the number of measurement units (ridges, fingerprints)used to calculate mean epidermal ridge breadth (MRB). Therefore, in future research, it would be advisable to introduce computation with interval estimates of MRB or a hierarchical approach directly accounting for individual epidermal ridges.