Stability of Lip Print Patterns in a Patient with Recurrent Aphthous Stomatitis (RAS) for Forensic Identification: A Clinical Case Report

Abstract

Recurrent aphthous stomatitis (RAS) may temporarily alter the surface characteristics of the labial mucosa and can therefore influence lip print recording in cheiloscopy. This clinical case report aimed to assess the stability of lip print patterns in a 24-year-old woman with recurrent minor RAS affecting the inner aspect of the left lower lip. Lip prints were recorded at three observation points: before lesion onset, during the active lesion phase and after complete healing. The lipstick-and-transparent adhesive tape method was used, and the obtained prints were transferred to white paper and photographed digitally. Lip print patterns were analysed using the Suzuki and Tsuchihashi classification after division of the lips into eight quadrants. At baseline, 199 grooves were recorded, with Type I′ being predominant (53.2%), followed by Type II (29.6%), Type V (8.5%), Type I (7.5%) and Type IV (1.0%); Type III was absent. During the active lesion phase, 115 grooves were identified, with an increased proportion of Type II (36.5%), reduced Type I′ (28.7%) and the appearance of Type III (0.9%), along with higher proportions of Type IV (12.2%) and Type V (10.4%). After healing, 80 grooves were recorded, and Type I′ again predominated (48.75%), followed by Type I (21.25%), Type II (12.5%), Type V (10%), Type IV (5%) and Type III (2.5%). These findings suggest that the basic lip print pattern in this case remained broadly stable, although active RAS was associated with temporary local distortion. Cheiloscopy may remain useful for forensic identification when the clinical condition of the lips at the time of recording is carefully considered.