Milk teeth have not fallen out of the new teeth grow out, according to the situation of permanent teeth eruption, choose to chew harder food to promote the root resorption of milk teeth, or extraction of milk teeth. 1. Chewing harder food to promote the root resorption of milk teeth: milk teeth have not fallen out of the gums of the new teeth have just erupted, in this case, you can let the child eat some harder food, on the one hand, to promote the development of the jawbone, on the other hand, to promote the root resorption of the milk teeth, so that the permanent teeth have enough space to erupt. 2. Extraction of milk teeth: If the milk teeth have not fallen out and the new teeth have already erupted and reached the occlusal plane, the milk teeth must be extracted in this case. If the baby tooth is loose, surface anesthesia can be used for extraction; if the baby tooth is not loose, it needs to be extracted under local anesthesia. If the milk teeth are not lost and the new teeth are erupted, go to the hospital in time and choose the best treatment plan after the professional doctor’s examination.