Interpapillary lines - The variable part of the human fingerprint

The dermatoglyphic pattern of human palms and soles is individually unique and unchanging. Their prints show the course of the papillary ridges as pap illary lines. Case reports and a few older studies of repeatedly taken fing erprints could. however, show that so-called interpapillary lines can devel op between the papillary lines. The questions of this study were: How often do interpapillary lines occur? Can the differences between papillary and i nterpapillary ridges be quantified? Five-hundred and two ink prints of the palms and fingers from the archive o f the Bochum Police Department were examined retrospectively. In 121 volunt eers, the appearance of interpapillary lines was examined prospectively. Fr om the later collective, the fingerprints of 13 people with interpapillary lines and nine people without were examined further by laking two silicon p rints and measuring them with laser profilometry. In 215 of the 502 ink prints (42.8%) interpapillary lines could be demonstr ated. In those subjects younger than 20 years they were less frequently obs erved (34.1%) than in those above the age of 20 (51.8%). Tn all cases using laser profilometry the interpapillary lines could be related to a correspo nding interpapillary ridge. The interpapillary ridge heights were 24.9 +/- 10.0 mum, significantly lower than the papillary ridges, which measured 59. 0 +/- 19.2 mum. Inter papillary ridge widths were with 194.8 +/- 65.1 mum s ignificantly narrower as compared to 435.5 +/- 57.4 mum in the papillary ri dge. Those papillary ridges, between which interpapillary ridges were found , were significantly further apart from each other (610.5 +/- 78.9 mum) tha n those without interpapillary ridges (484.9 +/- 70.6 mum). During the course of a lifetime new ridges between the regular papillary ri dges can develop or manifest. The fact that interpapillary lines are mon fr equently found on the right hands in men and those with increasing age is c onsistent with the theory that they correspond to degenerative changes and with sensitivity of touch.