In fact, it is a question of whether a decayed tooth should be pulled or filled with reference to the age factor; in general, the decayed tooth must be treated if it is not yet in the deciduous stage. Tooth extraction will affect the child’s feeding, and indirectly affect the nutrient absorption, resulting in the child’s developmental delay. Tooth decay of milk teeth, should be filled in time Tooth decay of milk teeth is not only painful, but also very bad for baby if no measures are taken in time. Because if the decay of the baby teeth, which will lead to periodontitis or pulpitis, and infect the permanent tooth embryo, resulting in the incomplete development of the permanent tooth enamel, will affect the baby’s permanent tooth eruption. If the baby teeth fall off prematurely, the permanent teeth that grow next to the baby teeth will occupy its position, and the permanent teeth that should grow under the baby teeth will be “homeless” and will struggle, and the teeth will be misaligned and uneven, which will affect the beauty. Moreover, the cavities of the decayed milk teeth will also make the baby painful when eating, which will affect the baby’s eating and thus the baby’s development. Due to the pain, the baby will be used to chew with the other side of the teeth, which will make the baby’s jaw bone development asymmetrical. Another common problem during the teething period is that the baby teeth have fallen out and the permanent teeth have not yet erupted. This problem can be divided into two cases: one is that the child’s milk teeth are not well protected, the teeth are broken and fall out early, for this reason parents do not need to be too anxious, you can take the child to the hospital to take a dental X-ray to see if the embryo is there, if there is then wait for the permanent teeth will slowly erupt; but if you can not see the obvious embryo, it may be another situation, that is, congenital permanent tooth loss, this situation is relatively rare, you can find a doctor to repair. This is rare and can be restored by a doctor. Nowadays, there are many children who have orthodontic treatment, and some bad habits during the tooth replacement period can lead to misalignment of teeth in the future. It should be reminded that finger-sucking is a behavior that infants and toddlers initially learn as a neurological reflex, and if it continues after the age of 4-6, it is a bad habit that can lead to obvious teeth misalignment, such as thumb-sucking, when the thumb is placed between the upper and lower front teeth that are erupting, it will affect the normal eruption of the front teeth and cause the front teeth to bite. In addition to finger sucking, there are also licking, pencil biting, lip biting and sideways chewing, etc. Children should pay particular attention to correcting these bad habits during the tooth replacement period to prevent future malocclusion.