You mean the teeth are locked, right? They often say that. Under normal circumstances, after 13 years old, teeth will be corrected and permanent teeth will all grow out. But because the land is special, it is often bone, so if it is land, it will usually be corrected after all the 4-year-old deciduous teeth grow out. At this time, the child's bones are still soft and relaxed. If not corrected, the growth of permanent teeth will be affected, which is also an overwhelming state. In a word, you'd better take the children to have a check-up.