Whether or not a tooth can be straightened after a traumatic injury depends on the extent of the injury as well as the location of the tooth. Dental trauma refers to teeth subjected to a variety of mechanical external forces resulting in sharp damage to periodontal tissue, pulp tissue and dental hard tissue. Clinically, it is divided into the following types: 1. Dental concussion injury: there is no change in the appearance of the teeth, due to periodontal tissue congestion teeth have a slight soreness, clinical treatment is based on observation. This situation can be corrected. 2. Tooth fracture: It is also divided into incomplete crown fracture, crown fracture, root fracture, crown-root fracture. Treatment according to include bonding, crown restoration, pile core crown restoration and so on. Orthodontic treatment is not recommended in this case. After the teeth have been traumatized, you should go to the hospital in time, make clear the degree of tooth damage through X-ray examination, and carry out timely treatment to prevent further deterioration of the condition.