1. Basic knowledge of children’s tooth replacement. Children’s tooth replacement refers to the process in which deciduous teeth are gradually replaced by permanent teeth. It usually starts around 6-7 years old and is completed around 12-13 years old. During this process, some children may experience early or late tooth loss, but these are normal changes. 2. Sequence Chart of Teeth Replacement in Children The following is the sequence chart of tooth replacement in children: 1. Maxillary central incisor (