It doesn’t matter if the baby teeth are decayed or not, the view is absolutely wrong. First of all, we need to understand the normal function of baby teeth. Baby teeth have 1, chewing function 2, beautiful pronunciation function Liang Hui, Department of Pediatric Stomatology, Urumqi Stomatological Hospital 3, the function of inducing the normal eruption of permanent teeth below 4, promote the normal development of the face. Let’s talk about the danger of baby teeth decay. 1, when the decay involves more than one milk molar, it can obviously reduce the function of chewing. The chewing function of children. Food is not easy to be cut off and chewed, which is not good for the digestion and absorption of food and affects the nutritional intake of children, and may also lead to partiality of children, who do not like to eat meat, vegetables, fruits and other food that are not easy to chew, which affects the growth and development of the whole body. We often see in the clinic that children with many serious caries are small and thin. When the bad teeth are concentrated in one side, it will form the habit of chewing on the side, which will lead to the asymmetric development of children’s jaws and face. 2.The food residue stays in the cavity and the bacteria gathers, so that the oral hygiene deteriorates and affects other teeth including permanent teeth to have caries. 3.Usually, the permanent teeth of the milk teeth are under the root of the milk teeth, when the inflammation around the root of the milk teeth, it will affect the normal development of the permanent teeth, and affect the eruption order and position of the permanent teeth, and if it is serious, the enamel development of the permanent teeth will be obstructed and the teeth will be malformed. 4.The premature loss of milk teeth due to caries, the teeth before and after will move like the gap, often cause the gap below the eruption of permanent teeth is too small, and cause the permanent teeth can not erupt normally. 5.The decayed and broken crown of the baby tooth is easy to damage the local oral mucosa tissue. It will cause local traumatic ulcers in the oral cavity. 6.The development of caries of milk teeth into periapical disease can cause focal infection to other tissues of the body as focal tooth. 7.It affects the beauty and correct pronunciation, and also causes some influence to the children’s psychology. Therefore, the caries of milk teeth should be treated as early as possible.