The appearance of cracks on the dorsal surface of the tongue in different directions, with different numbers, depths and lengths, is called “grooved tongue” or “cracked tongue”, which often occurs simultaneously with map tongue. The cause of the disease is not yet clear, mainly related to the following factors: congenital factors, such as abnormal tongue development; acquired factors, such as geographic environment, vitamin deficiency, plant nervous disorders; certain systemic disease factors, such as aspergillosis, May-Roth syndrome, dry mouth; infectious factors, such as viral infections, allergic reactions, etc.. It can occur in both men and women, and can gradually worsen with age. Cracked tongue commonly has a longitudinal crack in the center of the back of the tongue, which is often deep and divides the tongue into two halves; or there is a shallow transverse groove perpendicular to the longitudinal groove, like a leaf vein, called “leaf vein tongue”; or like a cerebral gyrus, called “cerebral tongue “Some of them have longitudinal and transverse fissures on the whole back of the tongue. Although the depth, length and thickness of the grooves vary, they do not affect the activity and taste of the tongue, and the tongue papillae are normal. Cracked tongue patients generally have no conscious symptoms, so generally do not need treatment. Deeper grooves often have bacteria and food debris retention in the grooves and mild inflammation, and sometimes may be painful, especially when stimulated, acid, heat and other food is obvious. Patients should pay attention to keep the mouth clean, rinse the mouth after meals, use the tip of the tongue to lick the tongue side of the lower front teeth (the purpose is to make the back of the tongue fully spread, exposing the bottom of the cleft groove) to rinse, to prevent food debris and bacteria in the cleft.