The main purpose of primary (baby teeth) molars is chewing. Space preservation, to allow eruption of permanent teeth is another important function that can be overlooked. Keeping a baby tooth until the permanent tooth is ready to erupt usually provides enough space for the permanent tooth to come in without causing crowding.
Occasionally a posterior baby tooth can be lost prematurely due to injury, tooth decay or an infection. If this occurs before the permanent tooth is ready to erupt the adjacent teeth can drift or shift into the space where the primary tooth used to be. This will reduce the amount of space that is available for permanent tooth eruption. In a situation where an upper or lower tooth doesn’t have an opposing one, it can drift vertically, up or down, to fill in the gap. If crowding of teeth occurs, the permanent tooth might come in lopsided, rotated, or it may not come in at all. Usually this condition can only be corrected by wearing braces for an extended period of time or other corrective treatment. Some of the long-term problems caused by crowding of teeth can include difficulty with keeping the teeth clean, which eventually can lead to tooth decay. Bone loss between the teeth can also occur in certain situations. Another common problem is difficulty with chewing food because of an unstable bite and reduced chewing surface area. The surface of teeth can also wear down excessively because the stress that is exerted on teeth is not distributed evenly.
Posterior permanent teeth that replace baby teeth usually erupt between the ages of 12-14. Maintaining the space until the permanent teeth are ready to erupt is crucial after premature loss of a baby tooth. Space maintainer is a small metal device that can be custom fabricated to fit the child’s teeth. It usually consist of an orthodontic band or a metal loop that is attached to a tooth on one side and a wire loop or spring bridging the gap to the tooth on the other side. The space maintainer will stabilize the remaining teeth until the permanent tooth is ready to come out. The space maintainer is usually removed when the permanent tooth begins braking through the gum tissue.