There is no relationship between the child’s five and a half year old tooth replacement and IQ, the child’s tooth replacement is determined by the law of tooth development itself. The first order of tooth replacement is to replace the middle teeth below and then the top teeth, and to replace the front teeth first and then the back teeth, generally speaking. However, there is a big individual difference in the time of tooth replacement, some children change their teeth at the age of seven or so. Some children are five and a half years old, or even earlier at the age of five also see the case of tooth replacement, so do not worry, the child’s tooth replacement and the child’s IQ development does not have any relationship, there is no tooth replacement early smart or not smart statement. During the child’s tooth replacement, we should maintain oral hygiene, regular review, refer to the general rule of tooth replacement in front, timely detection of abnormalities in time to adjust and timely treatment.