A child’s failure to lose teeth may be related to heredity, diet, normal phenomenon, and missing permanent teeth. 1. Heredity: If there is a family situation of late tooth loss, then his offspring may appear late tooth loss, each child will be different, it is recommended that you can eat some harder food to help promote the development of teeth. 2. Diet: children in ordinary life diet is more delicate, lack of intake of coarse grains will lead to delayed absorption of the root of the teeth, there will be the case of late tooth loss. 3. Normal phenomenon: there are differences between the physical quality of each child, the development is not the same, while the teeth are not often wear and tear, these will cause the child does not fall out of the situation. 4. Missing permanent teeth: When the permanent teeth embryo is missing under the milk teeth, the milk teeth will probably not fall out, will stay in the mouth, this situation can not be dealt with, so that the milk teeth to play the function of chewing, to be restored when it falls out. Suggested to the hospital to take a dental film, the doctor will be based on the situation to give judgment, usually in life to increase the child’s chewing function.