After children lost their milk teeth, they should take the appropriate treatment according to their age and the growth and development state of their milk teeth, as follows: 1. If the early milk teeth are lost due to trauma, afterwards, they need to protect the trauma, and at the same time make gap retainers for the lost milk teeth to keep the relative integrity of the teeth. After the loss of milk teeth, it is also necessary to take pictures to check the growth and development of permanent teeth, the injury of alveolar bone, etc. It is necessary to review regularly, and it is recommended to have a clinical examination once in 3-6 months, and to take pictures once a year to see if the growth and development of permanent teeth are affected. The growth and development of permanent teeth can be observed without special treatment. After the loss of milk teeth, we must make a comprehensive consideration and judgment to see the growth and development of permanent teeth, and then take the corresponding treatment method.