Tooth decay, gingivitis or loose teeth may occur after orthodontic treatment. Orthodontics is the process of bonding brackets to the teeth and then applying external force to the teeth to achieve tooth movement. After orthodontic treatment, tooth decay, gingivitis or tooth loosening may occur. The area around the tooth bonding brackets tends to retain food, which is not easily removed in time, and the teeth may become demineralized, which may cause tooth decay if not treated in time. Orthodontic treatment may also lead to dentin hypersensitivity of teeth. If the oral hygiene is not good after orthodontic treatment, food residue or soft scale accumulation around the teeth may cause gingivitis, redness and overflowing blood around the gums, bleeding from brushing teeth or eating. Prompt scaling and then dental rinsing and medication are needed. After orthodontic treatment, the teeth have not yet reached a new dynamic balance in the new position, the muscle balance has not yet been established, and the teeth can cause relapse to varying degrees. If the force exerted on the teeth during the movement of orthodontic teeth is too great, it may cause loosening of the teeth and different degrees of tooth root resorption. Therefore, after orthodontic treatment, tooth demineralization, gum bleeding or root resorption and tooth loosening may occur.