Diversity of human lip prints: a collaborative study of ethnically distinct world populations.

Background: Cheiloscopy is a comparatively recent counterpart to the long established dactyloscopic studies. Ethnic variability of these lip groove patterns has not yet been explored.

Aim: This study was a collaborative effort aimed at establishing cheiloscopic variations amongst modern human populations from four geographically and culturally far removed nations: India, Saudi Arabia, Spain and Nigeria.

Subjects And Methods: Lip prints from a total of 754 subjects were collected and each was divided into four equal quadrants. The patterns were classified into six regular types (A-F), while some patterns which could not be fitted into the regular ones were segregated into G groups (G-0, G-1, G-2). Furthermore, co-dominance of more than one pattern type in a single quadrant forced us to identify the combination (COM, G-COM) patterns.

Results And Conclusion: The remarkable feature noted after compilation of the data included pattern C (a bifurcate/branched prototype extending the entire height of the lip) being a frequent feature of the lips of all the populations studied, save for the Nigerian population in which it was completely absent and which showed a tendency for pattern A (a vertical linear groove) and a significantly higher susceptibility for combination (COM) patterns. Chi-square test and correspondence analysis applied to the frequency of patterns appearing in the defined topographical areas indicated a significant variation for the populations studied.