study of lip print patterns distribution and their stability in time pass

Background: cheiloscopy is a forensic investigation technique based on the identification of lip traces. this study sought to assess the distribution of lip print patterns and their stability during the time.methods: lip prints were obtained from 133 dental students and the distribution of patterns was evaluated, using the five-stage suzuki and tsuchuhashi's classification. six months later, lip prints were obtained again from 40 out of 133 students who were chosen accidentally to assess the stability. the individual lip formula was determined by paired t-test and anova at p<0.05. results: type i was the most common pattern in the lips. lip formulas were found to be unique for each individual. no significant difference existed in the distribution of lip print patterns between males and females, or between the upper and lower lips. in terms of stability, 73.8% of lip print patterns remained unchanged during a 6-month period. conclusion: lip print patterns are unique to each individual and have medium stability over time. therefore, cheiloscopy may be considered a useful identification tool in forensic dentistry. however, the lip print pattern cannot indicate the sex of people.