When a child’s tooth is knocked out, it needs to be treated separately after oral examination and taking full-mouth surface tomography, as follows: i. If complete dislocation of the baby tooth occurs and the tooth is intact, the isolated tooth can be disinfected within two hours, local anesthesia is administered and the tooth is reset in the alveolar socket, a full jaw pad is made and fixed, and the jaw pad is removed after the tooth root is stabilized for 3-4 months. Second, if the tooth is flush and the cervical part of the tooth is fractured, the pulp tissue can be removed directly, and the root canal opening can be closed by applying glass ionized cementum etc. after completing the one-time root canal treatment. If the fractured tooth is a baby tooth, you can wear a gap retainer and wait for the eruption of permanent teeth. If the fractured tooth is a permanent tooth, a pile crown can be made after the age of 16.