A baby tooth is sometimes lost prematurely because of tooth decay or injury. If a baby tooth is lost before the permanent tooth is ready to erupt, the nearby teeth can shift or drift into the space where the primary tooth used to be, creating a lack of space in the jaw for the permanent teeth. If this crowding happens, there may not be enough room for the new tooth to come in correctly, so it emerges lopsided or is not able to erupt at all. The gap left from losing this tooth needs to be held open for the permanent tooth to erupt in the correct position. A space maintainer keeps this space open for the permanent teeth and helps guide them into position. It’s a small metal device that is custom fitted to your child’s mouth, to be removed when the permanent tooth is in it’s proper position.