Some children will have mild pain during tooth replacement, some pain is not obvious, the specific pain feeling varies from person to person. Children generally begin to appear around the age of 6 years old milk teeth fall out, enter the tooth replacement period after most of the teeth in the age of 12 years old, replacement is completed, which is a normal physiological process, some children in the replacement of teeth may have a slight pain phenomenon, but most of the pain is not obvious, and the pain in the range of tolerance. Some children do not experience significant pain during tooth replacement, and the exact amount of pain varies from person to person. If small children change teeth during the obvious toothache, need to be alert to the possibility of disease, such as pulpitis, gingivitis, etc., the pain tends to be more intense, unbearable. Small children change teeth time if the tooth pain is more serious, should be timely to the hospital stomatology consultation, with the doctor to take treatment, usually should pay attention to dental cleaning.