Space maintainers can be very important to your child's dental development. A space maintainer is used primarily on children who have prematurely lost a baby tooth. If a baby tooth is lost early due to decay or injury, the surrounding teeth can shift to fill the empty space and can later cause difficulties when permanent teeth begin to erupt. A space maintainer can preserve the space for the permanent tooth, thus avoiding further crowding of the teeth in the future. The space maintainer is removed once the permanent tooth begins to appear.