Interpapillary lines--the variable part of the human fingerprint

Area of Science:

• Forensic science
• Dermatoglyphics
• Human identification

Background:

• Dermatoglyphic patterns, including papillary ridges on palms and soles, are unique and permanent.
• Previous studies and case reports suggest the potential development of interpapillary lines between existing papillary ridges.

Purpose of the Study:

• To determine the frequency of interpapillary lines in human fingerprints.
• To quantify the morphological differences between interpapillary and papillary ridges.
• To investigate potential correlations between interpapillary lines and demographic factors.

Main Methods:

• Retrospective analysis of 502 ink prints from the Bochum Police Department archive.
• Prospective examination of interpapillary lines in 121 volunteers.
• Quantitative analysis of ridge characteristics using laser profilometry on silicon prints from a subset of participants.

Main Results:

• Interpapillary lines were identified in 42.8% of the examined ink prints.
• Their occurrence was higher in individuals over 20 years old (51.8%) compared to those younger than 20 (34.1%).
• Laser profilometry confirmed interpapillary lines correspond to distinct ridges, which are significantly lower, narrower, and found between more widely spaced papillary ridges.

Conclusions:

• Interpapillary lines can develop or become apparent over a lifetime.
• The increased prevalence in older individuals and on men's right hands suggests a link to degenerative changes and tactile sensitivity.