Space Maintainers
One of (many) functions of baby teeth is to hold the space for the permanent teeth following after. Loss of a baby tooth early may lead to loss of space and impaction of the permanent tooth. The earlier the tooth is lost the more potential there is for the space loss.
The baby tooth itself is the best space maintainer and every effort should be made to keep these teeth healthy or to restore them to health if they are decayed. When extraction is necessary, space maintainers can be used to hold the space for the permanent tooth.