There are many reasons for white ulcers in the mouth, which may be due to the following reasons: 1. simple mouth ulcers, which can generally heal themselves within 10 days; 2. recurrent mouth ulcers, with long-term onset, rising and falling, and irregular location; 3. traumatic mouth ulcers, due to bad denture scratches, sharp root and crown scrapes, tooth bites, and hard food trauma; 4. chemical burns and hot and cold irritation injuries; 5. , Leukocephalus syndrome; 6. Heavy recurrent aphthous ulcers, also known as periglandular mouth sores.