Tongue print as a valuable biometric and forensic tool: A digital photographic study.

Background: Surface features present on the dorsal surface of the tongue along with colour and shape are unique characteristics of every individual. Tongue print is being considered as a new biometric and forensic authentication tool. This digital photographic study was conducted to analyze and compare morphological differences on the dorsal surface of the tongue which can serve as a valuable tool in forensic odontology.

Methodology: The present study utilized a digital photographic method. Patients who visited the outpatient department (OPD) of the dental institution for availing necessary dental treatment were included in the study. The final study sample comprised 316 subjects which were recruited by systematic random sampling. The shape, surface texture, colour etc. of the tongue were recorded. Descriptive statistics and chi-square tests were used for statistical analysis. Significance was set at p≤0.05.

Results: The majority of the subjects (60.13%) had a 'U-shaped' tongue. 'Tongue fissures/cracks' and 'Smooth Tongue' were the two prominent surface textures present among 59.18% and 35.13% of the study subjects respectively. The shape and surface texture of the tongue were significantly associated with the gender of the study subjects. Non-visibility of median septum was found more among females than males. More than two-thirds of the subjects (77.51%) belonging to the age group of 18-30 years had pink-coloured tongues and the findings were highly significant (p=0.00).

Conclusion: In addition to rugoscopy and cheiloscopy, the study of lingual morphology may be one of the secure methods for identification in forensic dentistry.