The top surface of a normal tongue is typically smooth, with a slight groove down the center (called the midline). However, if you were to look at your tongue under a strong magnifying glass or microscope, you would see that the top surface is actually covered by tiny raised structures. The most numerous of these are small, slender, cone-shaped structures called filiform papillae.
A fissured tongue is characterized by deep, branching grooves along its top surface, instead of just the normal midline groove. These grooves do not have the covering of filiform papillae, so they contrast sharply with the rest of the tongue's surface. They can vary considerably in length, depth and pattern, as well as in number. Fissured tongue can occur at any age, although the fissures tend to increase and deepen with age. This deepening invites the trapping of food and and debris (cells that have been shed) within the grooves. Normally a fissured tongue produces no symptoms, but a secondary bacterial or yeast infection can develop, causing soreness or a burning sensation along the tongue. When this occurs, the grooves become quitered and prominent. The adjacent papillae will often be shed as a result, and the tongue will have an inflamed appearance. Fissured tongue tends to be more common in people who frequently suffer from glossitis (an inflamed tongue), and especially in those with a condition called geographic tongue. The specific cause of fissured tongue has not yet been identified, but in some cases, it appears to run in families.
gently brush the surface of your tongue each time you brush your teeth (at least twice a day). This will minimize the chances of getting an infection on your tongue.