The study of inheritance analysis and evaluation of lip prints in individuals

Identification of an individual is a pre-requisite for certification of death and for personal, social, and legal reasons. The study of lip prints (cheiloscopy) was thought as a method for identification of a person. It is safe to assume that cheiloscopy, in its present stage of development, has become a means of criminalistic identification dealing with lip prints.

The first aim of the study was to evaluate the visible lip patterns in Rajasthan population in relation to the gender and to ascertain the existence of hereditary pattern followed among parents and offsprings. The second aim was to compare visible and latent lip print patterns on non-biological materials like tracing paper, microscopic glass slides and stainless steel tumblers.

The lip prints of 300 subjects including 25 families were obtained using lipstick. Out of these 300 individuals, 60 were selected for latent lip prints. In order to prevent any intra- and inter-observer variability single observer carried out all the observations. The lip prints were analyzed using magnifying lens and were classified using the criteria given by Suzuki and Tsuchihashi. The determination of the pattern in each segment of the lip was based on the numerical superiority of properties of the lines on the fragment.

After recording all the values for various parameters, data obtained were statistically analyzed with the help of the Statistical Package for Social Sciences software version-13 using independent t-test. For all the tests, a P value of 0.05 or less was considered.

In the present study, most predominant pattern in the entire study population among upper and lower lips considering both males and females was type III lip pattern. Hereditary resemblance was observed between parents and offsprings in 37.66%. The latent lip prints were better visualized on microscopic glass slide when compared to stainless steel tumblers.

Lip prints have a good potential for use in criminal investigations. They have been used only occasionally despite their frequent occurrence at crime scenes. A place for cheiloscopy is recommended within the scope of forensic odontology, along with other means of forensic identification.