A baby tooth stays in place until the permanent tooth, growing underneath, pushes it out and take its place. There are times when the baby tooth comes out too early. When this happens the permanent tooth may not be ready to take the place of the removed baby tooth. A space maintainer is used to hold the space until the permanent tooth is ready to erupt. Space maintainers are appliances made of metal or plastic that are custom fit to your child’s mouth. They are small, unobtrusive and in most cases kids adjust to them within a few days.