Generally children are 5 and a half – 6 years old after the beginning of tooth replacement, when the milk teeth gradually fall off, permanent teeth grow out one after another, about 12-13 years old to the end of tooth replacement, the medical period is called the period of replacement, mixed dental period. In addition, the age of children’s tooth replacement may be affected by external factors, but the order of tooth replacement is usually regular, the specific analysis is as follows: a. The age of children’s tooth replacement: 1, food impact: children who often eat harder food, may be early tooth replacement, children who often eat softer food, may be the time of tooth replacement will start relatively late; 2, nutritional factors: children are rich in nutrients when the body develops faster, may If children are malnourished for a long time will slow down the development of the body, causing a delay in the time of tooth replacement; 3, the gender factor: generally girls will mature earlier than boys, so the time of tooth replacement may also be earlier than boys. Second, the order of children’s tooth replacement: the order of children’s tooth replacement is regular, generally in the order of the first molar, central incisor, lateral incisor, first premolar, cuspids, second premolar, second molar, third molar (wisdom teeth). Generally, the first molars and central incisors start to be replaced at the age of 6-8, the lateral incisors and first premolars at the age of 8-9, the bilateral cuspids and second premolars at the age of 10-12, the second molars at the age of 12-13, and the third molars (wisdom teeth) at the age of 17-21. Caution: The healthy growth of teeth is related to calcium, phosphorus, fluorine, vitamin A, vitamin C, protein, etc. Therefore, during the period of tooth replacement, you should replenish the nutrition required by your body and keep it adequate and balanced, so as to facilitate the healthy growth of teeth.