Infants with ulcers in the mouth may be caused by a lack of certain trace elements in the body, such as vitamin B or zinc, so you can go to the hospital to check the trace elements and supplement vitamin B and zinc as appropriate after diagnosis. In daily life, parents are advised to pay attention to the nutritional balance of infants and toddlers, give them more fresh fruits and vegetables, and pay attention to oral hygiene. Younger infants can be helped by parents to brush their teeth, and they can also use light salt water to rinse their mouth during the ulcer growth period. When the ulcer is painful, you can also apply local painkillers, such as lidocaine gel, to relieve the pain of the child; you can also apply local growth factor gel, watermelon cream and other drugs to promote the healing of the ulcer. Ulcers will heal automatically in 7-14 days. Long-term untreated ulcers are recommended to be seen by a stomatologist.