Rapid Palatal Expander (RPE) screws were designed to be used for rapid expansion and separation of the mid-palatal suture. To be effective, they must always be used in a fixed approach, either banded or bonded. These screws are available in a variety of sizes and configurations, offering a large range in the amount of lateral expansion that can be accomplished. Although designed for rapid palatal expansion, these screws are frequently used as part of a fixed appliance that applies gentle forces for slow development.