Oral ulcers are a common disease in the department of oral mucous membrane, prevalent among people of all ages, especially in children and the elderly who have lower resistance. If oral ulcers are caused by residues in the mouth or stimulation from sharp teeth edges, known as traumatic ulcers, it is necessary to promptly remove the irritants for the ulcers to heal. If the irritant factors are not removed, the oral ulcers will not improve, and severe cases may lead to cancerous changes. Generally, oral ulcers can heal on their own in about two weeks, or 14 days. If the ulcers do not heal after two weeks and keep recurring without improvement, one should be cautious about the possibility of cancer and further biopsy should be conducted for assessment.