There is a mouth on the inner wall of the cheeks near the big teeth, which is considered to be caused by bad dietary habits, and may also be the emergence of mouth ulcers and other diseases. 1. bad eating habits: if you often eat spicy and stimulating food, do not pay attention to oral hygiene, may lead to the mucous membrane of the inner wall of the mouth is stimulated, so this symptom may occur, you can carry out dietary modification, maintain a light diet, and also need to be diligent in brushing and rinsing, to alleviate the symptoms. 2. Mouth ulcers: If mouth ulcers appear, it may lead to oral mucous membrane erosion, so this symptom may occur, can be used under the guidance of the doctor cedir iodine tablets, watermelon cream and other drugs treatment. Usually need to observe more physical symptoms, if there is an abnormality, it is best to consult a doctor in time for examination and treatment.