Comparative Assessment of Image-Based and Hand-Traced Methods in Lip Print Typing and Classification: A Cross-Sectional Study
N.I. Ranjana, T.N. Uma Maheswari, A. HaripriyaAbstract
Background:
Cheiloscopy, which involves the study of lip prints, is an essential aspect of forensic odontology. Digital photography and scanning are alternative modes that can be used to record the lip prints with a high possibility of achieving better images.
Objective:
The purpose of this study was to evaluate the accuracy of digital photography and scanning compared to the traditional method of lip print recording.
Methods:
Cross-sectional diagnostic accuracy study (May–September 2025) was conducted, where lip prints were collected from 75 subjects through conventional, digital, and scanning techniques; the sequence was randomized in all participants to avoid carryover effect. Each print was divided into 12 segments (S1–S12) and classified according to the Suzuki and Tsuchihashi system by two independent, blinded observers. Pattern distribution was analyzed descriptively, while inter-observer reliability and inter-method agreement were assessed using Cohen’s kappa (κ) with 95% confidence intervals.
Results:
Pattern types V and I predominated across most segments in all three methods. Inter-observer agreement was high for all techniques (κ = 0.792–1.000), with the highest consistency for digital photography.
Conclusion:
Digital photography and scanning showed excellent reliability and high agreement with the conventional technique, supporting their use as practical, standardized alternatives for lip print recording and classification in forensic investigations.