A palatal expander, also known as a rapid palatal expander, rapid maxillary expansion appliance, palate expander or orthodontic expander, is used to widen the upper jaw so that the bottom and upper teeth will fit together better. Palatal expansion is a combination of tooth movement and jaw expansion.
Expanders are custom-made for each patient and is either fixed or removable. The expander is attached to the upper back teeth and eases the center screw apart, which makes the upper jaw wider. As the jaw expands, new bone fills in between the two halves of the palate (called distraction osteogenesis). Expansion can take a few weeks to a few months, depending on the individual case. A rapid palatal expander (RPE), also known as a rapid maxillary expander (RME), is typically worn for four to six months.
