The corner of the mouth crack is usually a kind of stomatitis, the cause of the crack is mainly the following aspects: First, the patient due to severe dehydration, drinking too little water caused by the lips dry and cracked, the phenomenon of cracking, this time should be a small amount, many times to replenish water, so that the body’s intracellular water is sufficient, the corner of the mouth cracked situation will be alleviated. Second, due to excessive licking of the lips, so that the salts in the saliva on the skin of the corners of the mouth caused by the adverse effects of the phenomenon of cracking, this time requires patients should correct bad habits, try not to lick the lips or corners of the mouth. If you feel dry mouth, dry mouth, you can use water to moisten the corner of the mouth parts, so that its skin to moisturize the effect, in addition, you can also use some lip balm to keep the corner of the mouth moist, usually lip balm selection with Vaseline effect is better.