Children begin to give birth to their first permanent teeth at the age of about 6 years old, also called the first permanent molars, and then at the age of 6-12 years old, the child’s milk teeth will be gradually replaced by permanent teeth of the same part, the following precautions during the period of tooth replacement: 1, pay attention to oral hygiene: children in the period of tooth replacement must pay attention to the child’s oral hygiene, to brush teeth in the morning and evening, preferably after meals, and each brush should insist on at least 3 minutes, to do a thorough cleaning. To do a thorough cleaning, to prevent the child long oral diseases or dental caries; 2, exercise jaw bone development: during the tooth replacement period, the child can eat appropriate coarse food or hard things to exercise the jaw bone development, as well as the strong teeth and other conditions, try to avoid eating less sweets, these foods can affect the child’s dental health; 3, timely consultation: during the tooth replacement period, we should pay attention to take the child to the dentist regularly, so that the doctor to determine whether the child’s The child’s teeth development is normal, for example, whether there is misalignment or teeth bite problems, these diseases may lead to the child’s future jaw and oral dental development problems. Some children may also have delayed loss of baby teeth, which may affect the development of permanent teeth and may require extraction of baby teeth.