Mild pain may occur during orthodontic treatment. Orthodontics is a treatment that corrects malocclusion by aligning the teeth through the movement of teeth by applying a slow force to the teeth. Alveolar bone and periodontal membrane reconstruction is required to move the teeth during the orthodontic process. This is mainly because the teeth are held in the alveolar bone by the periodontium so that the teeth become loose. It is only then that the teeth can be shifted to their normal position, and at this point the teeth may experience some pain, but the pain is not very severe and can be tolerated by the patient. The first time the teeth are subjected to sustained external force during orthodontic treatment, they will feel sore and painful, which usually lasts for 3-5 days, and the pain symptoms will disappear. Teeth may also be worn because of the braces, making the gums and other soft tissues friction ulcers lead to patients with pain symptoms. After the teeth are straightened to the normal position and stop moving, the teeth can become stable through their own restorative ability to make the periodontal membrane reattachment and no permanent damage will occur, and the pain and soreness will disappear.