A look at all species of animals teaches us that only primates have fingerprints.  Only homo sapiens have fingerprint patterns made up of intricate loops and whorls.  Other primates just have straight parallel ridges.

OPPOSABLE THUMBS

This situation is because we have opposable thumbs.  We use our hands and fingers to sense and manipulate our environment.  The two purposes of fingerprints are to improve our grip on slippery surfaces and to enhance our sense of touch. 

TACTILE SENSITIVITY AND GOOD DENTISTRY

Tactile sensitivity is imperative to leaving smooth tooth surfaces during a professional dental cleaning and to building a filling or crown that exactly lines up with the margins on the natural tooth.  This so that bacteria can find no ledge or concavity in which to proliferate.  Smooth is the goal!

PACINIAN CORPUSCLES

Without good tactile sensation, we would not be able to tell the difference between silk and sand......tartar and enamel.   Our sense of touch comes from structures located a few millimeters below the skin surface called Pacinian corpuscles.   These cells are sensitive to pressure and vibration.

In effect, fingerprint ridges act like the needle in a phonograph.  A phonograph needle amplifies the vibrations of the needle against surface variations in the groove of a record to produce sound.  Fingerprints amplify the tiny vibrations from textures moving against the fingerprint ridges.  We perceive these vibrations with our Pacinian corpuscles and the brain interprets the information as texture.  The fidelity of our fingerprints is so fine that we can detect objects as small as one micrometer.  A human hair is 50 micrometers.

The loops and whorls also serve a function.  If they were parallel, we would only be able to detect vibrations coming from certain angles.  As it is, the loops and whorls give our fingers 360 degrees of fine tactile sensitivity. 

So you can thank our fingerprint patterns for fine quality dentistry!