Palatal Expansion

Palatal expansion is a combination of tooth movement and jaw expansion. It works by widening the two halves of the upper jaw, called the palate. The two halves are joined together by a “suture” in the middle of the roof of the mouth. The orthodontist custom makes an expander for each patient. An expander can be fixed or removable. The expander is attached to the upper back teeth and eases the suture apart, which makes the upper jaw wider. As the jaw expands, new bone fills in between the two halves of the palate. This process is called distraction osteogenesis. Expansion can take a few weeks to a few months, depending on the amount of expansion required for an individual patient.



A rapid palatal expander (RPE), also known as a rapid maxillary expander (RME), is generally worn from four to six months. During the first few weeks of wear it is necessary to expand (activate) the appliance. Depending on the appliance, the RPE may require activation with a special key or wrench. The orthodontist will provide detailed instructions on how to activate the appliance and operate it properly to achieve the desired results.


Palatal expansion improves the way the upper and lower jaws and the upper and lower teeth work. It widens the jaw so there is sufficient room for permanent upper and lower teeth to come in. Expansion can make the final smile broader and more attractive. Without expansion, and depending on the problem, permanent teeth may not have enough space to come in; or the lower jaw could grow out of proportion, which could require corrective surgery as an adult. Left untreated, a narrow palate can lead to excessive wearing of the teeth or the need for extensive dental work as an adult.

The orthodontist will advise the patient or parent on the need for expansion and which type of expansion is best suited to correct the problem. Expansion is easiest and results are most stable when performed on the growing child or teen. Age alone, however is not the best predictor of when a palatal expansion should be used. Ideally a patient should still be growing. Patients who have completed growth may require surgically-assisted rapid palatal expansion.


The orthodontist will recommend the type of expansion appliance necessary. Different appliances require different activation techniques. The orthodontist will provide specific instructions on how to expand the appliance and how often to expand it. It may take a few days to get used to the palatal expander. Chewing, swallowing and talking may be awkward at first. The mouth and nose may be sore or may tingle. Some patients report slight nasal pressure. The orthodontist may recommend over-the-counter analgesics to relieve discomfort. After a few days of expanding, the patient may notice space between the front teeth. This is a sign that the appliance is working and the palate is being expanded. Most patients require full orthodontic treatment (braces) following palatal expansion.


Care of the expansion appliance


The expander should be brushed whenever teeth are brushed. Patients should rinse their mouth with water after eating or after drinking a beverage with sugar. Removable expanders should be brushed and rinsed each time the appliance is taken out of the mouth.


Article Courtesy of the American Association of Orthodontists