The use of an Rapid Palatal Expander is the most commonly used form of transverse arch development and can be fabricated by using either a 2 or 4 band design or can be bonded using acrylic or a bioformed material. The screw variations come in a variety of sizes, depending on the desired amount of expansion needed, and configurations, either 2 or 4 arms. Recent developments have even led to screws that provide an audible "click" sound or feel to let the patient know when the proper amount of activation has been made.
