A space maintainer is an appliance that is custom-made by a dentist or orthodontist in acrylic or metal material. It can be either removable or cemented in a child's mouth. Its purpose is to keep the space open to allow the permanent tooth to erupt and come into place. Baby teeth are important to the development of the teeth, jaw bones and muscles and help to guide permanent teeth into position when the baby teeth are lost. If a space is not maintained, then teeth can shift into the open space and orthodontic treatment may be required. Not every child who loses a baby tooth early or to dental decay requires a space maintainer; however, a professional consultation with your dentist or orthodontist should be conducted to determine if using a space maintainer is needed.