When a baby tooth is lost early, or if a tooth never appears, a space maintainer is used to “save” a place for the permanent tooth (adult tooth).
If the space is not maintained, the teeth on either side of the missing tooth can move and prevent the permanent tooth from ever erupting. Also, without a space maintainer, teeth crowding can occur and be very difficult to treat.
A space maintainer is made of stainless steel and looks like a silver band and loop. Spacers are temporary and will be removed once the new tooth or teeth erupt, or the teeth around it become loose.