The baby teeth can influence the growth of permanent teeth and play an important role in the construction of permanent teeth (dentition). However, there are still many parents who believe that the baby teeth will be replaced by permanent teeth sooner or later, and it does not matter whether they are treated or not as long as the child does not scream for toothache. This view is extremely wrong. The disease with the highest incidence in the baby teeth is tooth decay. Tooth decay will lead to tooth loss, followed by pulpitis, periapical and periodontal tissue inflammation. When the pulp and periodontal tissue inflammation of the milk teeth is followed by the periapical infection of the milk teeth, or when the infection causes the solid adhesion between the roots and the alveolar bone, the resorption of the milk teeth roots will be incomplete or not resorbed at all during the period of tooth replacement, which results in the phenomenon of retention of the milk teeth and the misaligned eruption of the permanent teeth, leading to the occurrence of malocclusion. Similarly, the early loss of milk teeth not only deprives the eruption of permanent teeth, but also affects the beauty and pronunciation of young children, reduces the chewing function of young children, affects the digestion and absorption of food, disrupts the gastrointestinal function, leads to malnutrition and delayed development. Therefore, diseases of the milk teeth should be treated in time, only then can we reduce the occurrence of malocclusion (malocclusion) in permanent dentition and benefit the growth and development of children.