Why Does My Child Need an Expander?

When you bring your child into our orthodontic office to discuss potential early phase orthodontic treatment options, you may end up hearing your child needs a palatal expander. Not every child who undergoes early orthodontics will need one, but it could be beneficial in certain cases.

Expander for Teeth

A palatal expander is a small device that gets installed in your child’s palette – the roof of their mouth. This device consists of a metal base and wires that connect to the sides of the roof of the mouth and the upper teeth. Over time, this device is adjusted to put more pressure on the upper teeth to expand the palette.

Why might my child need an expander?

Normally, the upper teeth will fit slightly outside the lower teeth when your child bites down. However, some children’s jaws develop in a way where the upper rear teeth fit inside of the lower rear teeth when they bite down, which is also known as a posterior crossbite. When your child gets treatment with a palatal expander, the posterior crossbite is fixed and their jaw will bite down normally.

How long will an expander stay in?

Your expander will usually stay  in your mouth about five to six  months to allow the expansion to occur and for the new bone that has formed to mature. If an expander is removed too soon, some of the width gained could be lost. 

Types of Expanders

There are several different types of palate expanders. Some of the most common types of palate expanders include removable, rapid, surgically assisted and implant-supported.

Removable palate expander

A removable palate expander looks similar to a retainer that might be used to straighten teeth but it’s made from chrome instead of acrylic material. This option is typically recommended when the jaw only needs to be widened a little bit

Rapid palate expander

A rapid palate expander fits in the roof of your mouth and attaches to your back upper teeth. There’s a tiny screw in the middle that you turn a little bit every day with a special palate expander key. For younger patients, it’s recommended that an adult assists them with this.  Over time, this tension moves your two palatal bones apart to widen the jaw.

Surgically assisted rapid palate expander (SARPE)

Often, this type of palate expander is used either for adults who already have developed facial bones or for more severe cases in younger patients. An oral surgeon will place this expander in the middle of your upper palate (this line down the middle is called the suture). Similar to the rapid palate expander, this expander needs to be activated a little bit every day with a special key.

Implant-supported palate expander

For slightly older patients, this type of palate expander applies the force of an expander onto four mini dental impants rather than the natural teeth so more pressure is applied to the jaw rather than the teeth themselves. After treatment, the implants are then removed.

What is an Expander Key?

Your child or teen may receive a certain type of expander that requires routine adjustment by you, the parent or guardian. This is achieved with an expander key which, when inserted and turned, expands the hardware out so the upper jaw is gradually shifted out to a proper width. You will receive a key that is inserted into the center of the expander on the roof of the mouth.

 It’s easiest to have your child lay down with their head tilted back in an area that has plenty of good light when it is time to make an adjustment. The key is then inserted into the small hole at the center and you  turn the key in the direction indicated by the arrows on the expander. Your orthodontist will tell you how many turns and how often to turn it. 

What are you not allowed to eat with an expander?

Just like with other types of orthodontic appliances, there are some limitations to the kinds of foods you can eat with a palatal expander. Avoid sticky foods like taffy, gum. and carmel which can get caught on the appliance causing additional wear and tear. It is also important to avoid hard food like nuts, ice, popcorn and large pieces of raw carrots or apples.

Problems fixed with a palatal expander

A posterior crossbite can be problematic for many reasons. When the upper jaw is too small, the teeth that come in after the baby teeth don’t have enough room to erupt correctly. This leads to crowding, where teeth are tightly pressed against each other and may grow in crooked.

Crowded teeth not only result in a crooked smile, but they also increase the risk for long-term oral health problems since cleaning in between teeth is much more difficult. Posterior crossbites also increase the risk of impaction, which means the adult teeth never erupt and stay beneath the gums. Impaction can lead to chronic discomfort, jaw pain, or headaches. It can also lead to sinus problems due to pressure near the sinuses.

Also, when the upper teeth are positioned further inside the jaw than they are supposed to be, it can start to put pressure on the tongue. This results in a higher risk of your child biting their tongue on a regular basis and can make speaking more difficult. Having a posterior crossbite can also cause troubles when it comes to breathing. The excess pressure in the upper jaw can make breathing through the nose quite difficult, leading to mouth breathing. Getting an expander can remedy all of these issues while setting your child up for further success in their oral health down the road.

The jaw problems that lead to your child needing a palatal expander are often genetic, but they can also be the result of bad habits that don’t go away with age. For instance, if your child sucks their thumb past the age of four, this can cause problems with the way the upper jaw develops. There are ways to effectively stop your child from thumb-sucking to help avoid this issue.


If you think your child may benefit from an expander or other early orthodontic treatments, contact Smith Orthodontics today!