Individual Uniqueness of Cheiloscopy among Ikwerre Indigenes of Rivers State

Abstract

Background: Personal identification remains the primary goal of every forensic investigation. In the present study, lip print was considered as a tool in personal identification as well as establishing ethnic differences. Materials and Methods: The study involved 300 randomly selected subjects (72 males and 78 females) from the Ikwerre ethnic group in Rivers State Nigeria. A 500 watts Solar powered HPG 3110 Photo scanner was used to capture the lip print of the subjects. The lip was divided into four (4) quadrants and five (5) lip types were identified in each quadrant (Type I, I’, II, III, IV and V). Descriptive statistics (frequency) was done to determine the distribution of the lip print patterns, while chi-square test was done to determine the association between sex and cheiloscopy. Results and Discussion: In the upper left quadrant; Type I [53 (35.33%)] was the most occurring pattern, followed by II [28 (18.67%)], Type I’ [27 (18.00%)], Type IV [22 (14.67%)] and Type III [20 (13.33%)]. In the upper right quadrant; Type III [44 (29.33%)] was the most occurring pattern, followed by Type II [33 (22.00%)], Type I’ [24 (16.00%)], Type IV [20 (13.33%)], Type I [17 (11.33%)] and Type V [12 (8.00%)]. For the lower left quadrant; Type IV [42 (28.00%)] was predominant, followed by Type I’ [35 (23.33%)], Type II [28 (18.67%)], Type III [24 (16.00%)], Type I [16 (10.67%)] and Type V [5 (3.33%)]. While in the lower right quadrant; Type I [36 (24.00%)] occurred most, followed by Type IV [33 (22.00%)], Type III [30 (20.00%)], Type II [23 (15.33%)], Type I’ [22 (14.67%)] and Type V [6 (4.00%)]. Except in the lower right quadrant, sexual dimorphism was observed in all quadrants; upper right quadrant (X2 = 21.75; P-value = 0.001), upper left quadrant (X2 = 22.60; P = <0.01) and lower left quadrant (X2 = 20.15; P-value = 0.001). The most occurring pattern for the population was type I [122 (20.3%)], followed by III [118 (19.7%)], while the least was type V [23 (3.8%)]. Type III [Male (M) = 64 (22.2%); Female (F) = 54 (17.3%)] and V [M = 13 (4.5%); F = 10 (3.2%)] were predominant in male subjects. While Type I [M = 54 (18.8%); F = 68 (21.8%)], I’ [M = 50 (17.4%); F = 58 (18.6%)], II [M = 51 (17.7%); F = 61 (19.6%)], and IV [M = 56 (19.4%); F = 61 (19.6%)] were predominant in female subjects. Differences in the distribution of various types between male and female subjects were not statistically significant at p < 0.05. Conclusion: Lip print was observed to be unique among individuals and also sexually dimorphic when considered according to quadrants. This finding will serve as a useful tool in forensic investigations.