Children within one year of age, from four months should be cleaned out the mouth, because four months to start eruption of teeth, if the mouth has not been cleaned out before the age of one year, children are particularly prone to cause ulcers. After the ulcers recommended a method, very simple: 1, tin class San plus a prednisone, a vitamin B, a vitamin C, they are crushed into powder mixed together, sprayed on the surface of the ulcers. 2, every day to a large number of intake of vegetables, fruits. 3, stools must be smooth. 4, do not eat greasy food. If it does not get better, you can use interferon nebulization, there is a kind of medicine that acts directly on the surface of the ulcer through nebulization. So in summary: 1, clean up the mouth; 2, tin analogs plus a prednisone, a vitamin C and a vitamin B complex, mixed into a powder sprayed on the top of the ulcer; 3, more vitamins; 4, less greasy food; 5, stool must be fluent, seven days or so, the ulcer will slowly be good.