If the milk teeth have not fallen out and the permanent teeth have grown out, it is necessary to go to the hospital to remove the milk teeth in time. If the milk teeth are loosened more obviously, the milk teeth can usually be removed by applying surface anesthetic to the mucosal surface; if the milk teeth are not obviously loosened, it is necessary to apply local anesthetic to the gum area before they can be removed painlessly. In clinical practice, we have met many children with retained milk teeth, that is, the phenomenon of milk teeth not falling out and permanent teeth erupting ectopically, usually because the chewing food is too soft, resulting in delayed resorption of milk teeth roots, which cannot fall out by themselves and occupy space, so that permanent teeth cannot erupt normally. Therefore, children between the ages of 8 and 12 must eat hard foods to promote the timely loss of baby teeth.