Palate (Palatal) Expanders: Types, Treatment Indicators & More

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  • Source: NewMouth
  • 02/17/2022

What is a Palate Expander?

Palate (palatal) expanders are orthodontic appliances that create more space in a child's mouth by widening the palate (roof of the mouth) over time. The goal of palatal expansion is to widen narrow palates in children and correctly align the upper teeth and jaw. This treatment can only be completed before the jaw fully develops. The most effective way to prevent bad bites, crowded teeth, and other misalignment issues is to invest in palatal expansion at a young age.


Palate expanders widen narrow palates in children. They are used to prevent future orthodontic issues.

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. Common types of expanders include:

Rapid Palatal Expander (RPE)

The rapid palatal expander can correct narrow palates, crowding, and crossbites. The appliance fits 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 with a special key to create tension between the two palatal bones.
The goal is to widen the maxilla (upper jaw), expand the dental arch, and move the teeth within the bone. Over time, the two palatal bones move apart and the jaw widens. Most orthodontists also leave the appliance in for a few months after the desired expansion is achieved to allow new bone to form. In most cases, palate expansion treatment takes 3 to 6 months.
RPEs 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

Mature adolescents typically require implant-supported expanders. Once the jaw is almost fully developed, heavier forces are necessary to successfully widen the jaw and palate. 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 a person 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).


There are four palate expansion techniques: RPEs, removable expanders, implant-supported expansion, and surgically-assisted expansion.

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.

Crowded Teeth

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 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.
Before your child's adult teeth grow in, an orthodontist can check to see how much room is available in his or her mouth. If the jaw seems too narrow, palate expansion may be necessary to prevent dental crowding as the permanent teeth grow in.

Breathing Problems

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:
  • If the lower teeth and jaw are positioned in front of their upper teeth and jaw (underbite).
  • If 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).


Your child may require palate expansion if they have impacted teeth, a crossbite, crowded teeth, and/or breathing problems.
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