During the period of tooth replacement, attention should be paid to whether the milk teeth are retained or not, whether there is early loss of milk teeth, etc., as well as paying attention to oral hygiene and correcting bad habits. 1. Whether the milk teeth are retained or not: There is a certain time and order for milk teeth to fall out, and if they do not fall out when they should, it is called retained milk teeth. If the permanent teeth have already come out, but there is no sign of milk teeth falling out, it is easy for the permanent teeth not to erupt in the normal position. 2. Whether there is premature loss of milk teeth: If the milk teeth fall out before they should fall out, it is called premature loss of milk teeth, which will cause the neighboring teeth next to it to tilt towards the gap of missing teeth, making the gap of missing teeth smaller, and the permanent teeth will erupt in the wrong position due to insufficient gap. 3. Pay attention to oral hygiene: If the teeth are not cleaned properly, there will be food residues left in the gaps of the teeth, which can easily breed bacteria and cause dental caries. Dental caries will affect the growth of permanent teeth, and there will be misalignment of permanent teeth. 4. Correct bad habits: Do not lick the newly erupted permanent teeth with your tongue. Repeated licking will affect the growth direction of the newly erupted teeth. In addition, during the period of tooth replacement, you can let children eat more hard food, so that the milk teeth can fall out naturally. Parents should pay more attention to the situation and bring their children to the dentist of the regular hospital in time when there is any abnormality.