Study of lip print types among Nigerians.

Lip prints in a narrow sense are normal lines and fissures in the form of wrinkles and grooves present in the zone of transition of lips. The aims of this study were to determine the types and association of lip prints as well as the role of the lip print as genetic marker in ethnic differentiation in multi-ethnic population of Nigeria. A total of 820 individuals (414 males and 406 females) participated. The study sample was drawn from different ethnic groups of Nigeria. The three major ethnic groups were identified and the minor groups were lumped together. This was to provide clear evidence on the ethnic differentiation based on lip print types among Nigerians. The lip prints were collected on microscopic glass slides and developed using carbon black powder. Each print was then divided into 10 compartments and analyzed using a magnifying lens. Chi-squared test was used for association between ethnicity and lip print types; p<0.05 was set as a level of significance. The result of the study showed the following lip print pattern in Nigerian population where Type V (31.39%) was predominant, followed by Type III (24.18%), Type IV (18.70%), Type I (14.87%), Type II (10.29%) and least frequent was Type I' (0.57%). Statistically significant association (p<0.05) of lip print types with ethnicity was found in upper left lateral compartments (ULL). It was concluded that lip prints show ethnic differences. Hence, they may hold potential promise as a supplementary tool in ethnic differentiation and in personal identification.