When children are learning to walk they are especially likely to fall and injure their teeth or mouth. You should bring a child to see a dentist if they hurt their mouth and the bleeding doesn't stop, or if they damage a tooth, or if they fall and drive a tooth back up into their gum. Your dentist will be able to take an x-ray and decide if anything needs to be done. Very often, all that is needed after an injury is to keep a close eye on the child's teeth and gums for a while, but you should check with a dentist to make sure.