The child is six years old and still not losing teeth may be a normal phenomenon, but also may be a pathological phenomenon, such as retained milk teeth, permanent teeth obstruction, and so on. 1. Normal phenomenon: human teeth are divided into milk teeth and permanent teeth, generally around two and a half years of age, all milk teeth can be erupted, permanent teeth from the age of six years old, and gradually replace the milk teeth, for the normal alternation of milk and permanent teeth process. Due to the different growth and development of each child, if the milk teeth erupt later, the permanent teeth will also erupt later, so it may be a normal phenomenon that the teeth have not been lost at the age of six. 2. Retained milk teeth: Due to abnormal development of the teeth themselves, or changes in dietary structure, children’s diet is more refined and leads to decreased chewing power, affecting the absorption of the roots of the milk teeth, resulting in the retention of milk teeth, which leads to the situation that the six-year-old child has not lost his teeth. 3. Permanent teeth obstruction: the child is six years old and still do not fall out of the teeth may be related to the permanent teeth obstruction, if the development of the permanent teeth abnormalities, can lead to the permanent teeth eruption abnormalities, resulting in the child does not change the teeth, do not fall out of the teeth of the situation. If your child is six years old and has not lost his or her teeth, parents should take their children to the hospital in time to improve the relevant examinations and have the doctor carry out the appropriate treatment if necessary.