Comparison of Cheiloscopic Patterns in Twins Residing in a City of North Maharashtra- A Cross-Sectional Study

Abstract

Background: Within forensic odontology, cheiloscopy provides a minimally intrusive supplement to techniques like dactyloscopy by analysing distinctive lip print patterns for human identification. Similar to fingerprints, lip prints exhibit individual heterogeneity and stability, although research on twins is still scarce despite evidence of genetic implications. In order to evaluate forensic value, quadrant-specific matching, and genetic similarity, this cross-sectional study analysed cheiloscopic patterns in twins from North Maharashtra. Methods: Twins (n=25 pairs) were recruited from an OPD at the dental institution and local Gynecologist database. (March-November 2025). After ethical approval written informed consent per Declaration of Helsinki, lip prints were collected and imprinted on paper. Data analysed via Chi-square, unpaired t-test. Results: Of 25 twin pairs, 83.3% showed overall similar patterns (χ²=12.09, p=0.0005); 72% matched across all quadrants (p<0.028). Pattern distribution: Type I (28%), II (26%), III (18%), I' (14%), IV (12%), V (2%), with quadrant variations (e.g., Type I highest in third quadrant at 8.87%). Conclusion: Twin lip prints exhibit strong genetic similarity (83.3% overall) with quadrant-specific variations (28% unmatched), supporting cheiloscopy's forensic value for individualization, even among genetically similar individuals.

Keywords: Cheiloscopy; lip prints; twins; Suzuki-Tsuchihashi classification; forensic odontology.