Like a fingerprint, the tongue has its own shape and texture, and its tiny bumps and ridges are distributed in a way that is uniquely yours. These patterns rarely change over time since the tongue is protected inside the mouth (unlike fingertips, which may become scarred). Researchers are developing 3-D tongue imaging to aid in identification.
The tongue is a unique organ in that it can be stuck out of the mouth for inspection, and yet it is otherwise well protected in the mouth and is difficult to forge. The tongue also presents both geometric shape information and physiological texture information, which are potentially useful in identity verification applications.
Another interesting fact is that each person’s set of teeth is also unique — much like their fingerprints. Even identical twins do not have exactly the same set of teeth.
Picture Credit : Google