Patient: A year and a half after the upper incisor left tooth fell out, no new tooth erupted, I don’t know how it happened. Yang Jie, Pediatric Dentistry, Peking University Stomatology Hospital: There is a certain time sequence for the eruption of teeth, what you said should be the corresponding permanent teeth did not erupt after the loss of milk teeth, the maxillary central incisor (the first one in the middle) usually erupts from 7 to 7 and a half years old, and the lateral incisor (the second one) usually erupts around 8 years old. Therefore, the permanent teeth should not erupt after the milk teeth fall out, but also need to wait until the time when the permanent teeth should erupt. If the permanent teeth are not erupted at the time when they should be erupted, then you need to go to the hospital for examination. Yang Jie, Department of Pediatric Dentistry, Peking University Stomatology Hospital