The early or late tooth replacement has nothing to do with bone age, but is mainly determined by the formation of the tooth germ and other conditions in the mouth. If the patient’s milk teeth are missing too early, it is likely to stimulate the permanent tooth germ to develop and erupt too early, so as to exercise the chewing function. Girls change their teeth earlier than boys, but parents do not have to worry about the early or late change of teeth, because as long as the permanent tooth germ exists, the teeth will erupt sooner or later. If you are worried about whether there is an abnormality in tooth replacement, you can go to the hospital pediatric dentistry to take a full-mouth X-ray, through the X-ray film can clearly see the permanent tooth germ that will be replaced, as long as the permanent tooth germ exists without missing, then the permanent tooth will definitely grow out.