dental instruments and oral health

What is a Palate Expander?

The best way to prevent major malocclusions (incorrect bites) is to receive orthodontic treatment at a young age. Palate (palatal) expanders are common orthodontic appliances that create more space in a patient’s mouth by widening the upper jaw over time.

Palatal expansion, also called maxillary expansion, widens extremely narrow palates in children by correctly aligning the upper jaw and teeth.

Types of Appliances and How They Work

Expanders are uniquely made for each patient based on their dental arch and palate size. The devices come in fixed and removable forms. Depending on the patient’s needs, an orthodontist will determine the best treatment option for their unique situation and desired outcome. Common types of expanders include:

Rapid Palatal Expander (RPE)

The rapid palatal expander can correct narrow dental arches, crowding, and crossbites. The appliances fit over a few back teeth in the upper jaw with a screw in the middle. To activate an RPE, you turn the screw a small amount each day to create tension between the two palatal bones.

In short, the goal is to widen the maxilla (upper jaw), expand the dental arch, and move the teeth within the bone. Over time, the jaw widens. In most cases, palate expansion treatment takes 3 to 6 months.

They can widen the upper jaw at a rate of 0.5mm per day. Slow palate expansion can also be achieved by widening the upper jaw at a rate of 0.2mm per week.

Removable Palatal Expander

An orthodontist typically indicates a removable expander when a patient only needs minor jaw widening. These appliances are similar in appearance to acrylic retainers, except they are chrome.

Implant-Supported Expansion

More mature adolescents typically require implant-supported expanders. Once the jaw is almost fully developed, heavier forces are necessary to widen the jaw and palate successfully. This expansion treatment consists of four mini-implants that apply force directly to the maxillary bone, instead of the teeth.

Surgically Assisted Palatal Expansion

Once an individual reaches full maturity (puberty), they typically have a fully developed jaw. Although, some jaws do not fully mature until age 21 to 25. If this is the case, an orthodontist must surgically insert an expander into the mid-palatal suture (palate bone).

When is Palate Expansion Necessary?

The three most common circumstances that typically indicate the need for maxillary expansion include:

Impacted Teeth

When a tooth is stuck under the gums and blocked by other teeth, it is an impacted tooth. Dentists recommend extractions to reduce the chance of disease and jaw misalignment. Palate expanders can help widen the jaw and allow for the proper eruption of permanent teeth.


A crossbite is when the upper and lower teeth do not align correctly when biting down. Crossbites occur when some bottom teeth are located outside the upper teeth when the two jaws are closed. This type of malocclusion can sometimes be corrected with palate expansion treatment.

Teeth Crowding

Over-retained teeth refer to baby teeth that have loosened but then tighten back into the gums, preventing the eruption of permanent teeth. If the primary teeth are not extracted, dental crowding commonly develops, which is a condition that occurs when there is not enough space for teeth to grow in. Palate expanders eliminate the need for extractions and create space for permanent teeth to grow in.

Improved Breathing

Maxillary expansion can also improve breathing ability, which helps prevent mouth-breathing and dry mouth (xerostomia).

Maxillary expansion also treats Class III orthodontic problems. Class III problems are primarily genetic and may include:

  • When a patient’s lower teeth and jaw are positioned in front of their upper teeth and jaw (underbite).
  • When the lower jaw appears to be unusually large. Although, the lack of upper jaw development is usually the actual cause of this abnormality.

Palate expanders also treat maxillary transverse deficiency. Patients with this condition usually have a narrow palate and posterior crossbite. Other indications of maxillary transverse deficiency include:

  • Paranasal Hollowing when the bones of the upper jaw are underdeveloped, the lower jaw excessively protrudes forward.
  • Narrow Nasal Base instead of having wide nostrils, a person with maxillary transverse deficiency may have unusually narrow or thin nostrils.
  • Deepened Nasolabial Folds indentations that extend from the nose to the outer corners of the mouth. The indentations, or lines, are more noticeable when smiling.
  • Hypoplastic Zygoma a person with hypoplastic zygoma has underdeveloped and flattened cheekbones.
  • Narrow Tapering Maxillary Arch an extremely narrow palate (v-shaped).

Indicators for Palate Expansion

Before the end of an adolescent’s growth spurt, palate expansion can be done. Although, depending on the patient’s age, expansion techniques vary. For example, treatment is different for adolescents in the primary dentition phase (baby teeth), early mixed dentition phase (mix of baby teeth and permanent teeth), and early permanent dentition phase (all permanent teeth).

Palate Expansion Primary and Early Mixed Dentition

Expansion of the palate is most effective when the bone sutures have not yet fused and the patient’s jaw is still growing. As baby teeth fall out, permanent teeth start to erupt around the same time (age 6). When the dentition consists of some primary teeth and permanent teeth, it is the “mixed dentition phase.” If a child has a crossbite or crowded teeth during this phase, palate expansion may be necessary.

Palate Expansion Preadolescents (Late Mixed Dentition)

As an adolescent reaches the late mixed dentition phase, which is when there are more permanent teeth in the dental arch than primary teeth, palatal expansion is more difficult. During this phase, the bone sutures begin to fuse and the jaw isn’t growing as quickly. It is typically necessary to wait until the first premolars erupt to begin expansion treatment.

Palate Expansion Early Permanent Dentition

As an adolescent’s growth spurt ends, palatal expansion may not be possible. This is because the jaw is almost fully developed and the bone sutures have fused. Implant-supported or surgically assisted palatal expansion is typically the only treatment option at this stage because heavier force is needed to expand the jaw. Expansion is more likely to be successful in young children rather than those who have reached mid or late adolescence.

Common Questions and Concerns

Do Palate Expanders Hurt?

No, fixed and removable palate expanders do not hurt. Once you activate the device, your child may feel some pressure for a few minutes.

However, implant-supported and surgically assisted expanders may cause discomfort for a few days post-op.

Do They Work for Adults?

Orthodontists do not recommend palate expanders for adults because jaws and palates fully develop in the early 20s (at the latest). Expanders are most effective when the bone sutures have not fully formed yet.

How to Eat with Expanders

All types of expanders, including removable expanders, are completely safe to eat with. In fact, chewing forces increase the effectiveness of palate expanders. Although, orthodontists recommend cutting food into small pieces because eating large pieces of food can lead to choking.

How to Clean Palate Expanders

For the best results, most patients brush their appliance and teeth in between meals. Antimicrobial mouthwash can also help remove any food and bacteria stuck under the expander.