Gingival flesh cracked open a crack caused by gum inflammation or trauma. 1. Inflammation of the gums: just cleaned the surface of the teeth, saliva in a few minutes will form a thin film, bacteria in the mouth will begin to adhere to this film, accumulation, reproduction, and gradually matured to form plaque, plaque can not be washed away by the water or gargle off, and will be mineralized into tartar. The surface of tartar adsorbs a large number of bacteria, and its removal is more difficult, tartar itself will also stimulate the surrounding gums. The longer plaque and tartar stay on the surface of the teeth, the greater the stimulation of the gums, which can lead to a crack in the gums. 2. Trauma: Damaged or cracked gums caused by external impact. Gum problems need to go to the hospital in time for standardized treatment.