Most of the children’s teeth replacement age is about 6 to 12 years old, from about 6 years old to begin to replace teeth, to about 12 years old can basically replace the completion, if the early eruption or eruption is too late, you can go to the hospital in time to check and intervene. Children start teething at around 6 months of age, and at around 3 years of age, there are 20 milk teeth, or baby teeth, in the mouth, which will theoretically be replaced with permanent teeth. Children begin to change their teeth around the age of 6, starting with the incisors, and the first permanent molars erupt at the same time. The fourth baby tooth is replaced as the first premolar around the age of 7-9 years, the fifth baby tooth is replaced as the second premolar around the age of 10-12 years, and the second permanent molar and cuspids erupt at the same time around the age of 12 years.