Mind the gap: overview of space maintaining appliances

The primary teeth are imperative in a child's growth and development. They are vital for mastication and speech, but they also have an important role in the guidance and eruption of permanent teeth by acting as natural space maintainers (Figure 1).

Figure 1.Primary teeth have come out, leaving space for permanent teeth

When a primary tooth is congenitally absent or lost prematurely due to severe caries or trauma, it can lead to mesial movement of the remaining teeth and reduction in arch length that can in turn result in malocclusion in the permanent dentition in the form of crowding, crossbite, ectopic eruption, overeruption, poor molar relationship and excessive overbite and overjet. A dental appliance called a space maintainer can avoid these consequences and prevent or reduce the need for future orthodontic treatment.