What Is a Palatal Expander?
A palatal expander is a custom-made orthodontic appliance that fits across the roof of the mouth (palate). It attaches to the upper back teeth and has a small screw mechanism in the center. When the screw is turned, it pushes outward on both halves of the upper jaw, gradually widening it.
In children and young adolescents, the upper jaw is actually two separate bones joined in the middle by a flexible cartilage connection called the mid-palatal suture. A palatal expander takes advantage of this natural growth area by separating the suture slowly and predictably. As the bones move apart, new bone fills in the gap, creating a permanently wider upper jaw.
This type of expansion is called orthopedic expansion because it changes the bone structure, not just the position of the teeth. It is different from simply tipping the teeth outward, which does not address the underlying skeletal problem.
When Is a Palatal Expander Needed?
An orthodontist may recommend a palatal expander for several reasons. The underlying issue is always that the upper jaw is too narrow relative to the lower jaw or to the space needed for the permanent teeth.
Common Reasons for a Palatal Expander
- Posterior crossbite: When the upper back teeth sit inside the lower back teeth instead of outside them. This is the most common reason for palatal expansion.
- Crowding: When there is not enough room in the upper arch for all the permanent teeth to come in straight. Expanding the jaw creates space without needing to extract permanent teeth.
- Narrow upper jaw (maxillary constriction): Some children have an upper jaw that is visibly narrow, which can affect breathing, facial symmetry, and bite alignment.
- Impacted teeth: A narrow palate can block permanent teeth, especially canines, from erupting into their correct positions. Expansion can create a path for these teeth.
- Breathing and airway concerns: A narrow upper jaw reduces the volume of the nasal cavity. Expanding the palate can improve nasal airflow in some children, though this is a secondary benefit, not the primary reason for treatment.
Types of Palatal Expanders
Several types of palatal expanders exist. The orthodontist selects the type based on the patient's age, the amount of expansion needed, and whether the mid-palatal suture has begun to fuse.
Rapid Palatal Expander (RPE)
The rapid palatal expander is the most commonly used type. It is a fixed appliance cemented to the upper molars with bands or bonded to multiple teeth. A jackscrew in the center is turned once or twice daily with a small key. Each turn widens the expander by approximately 0.25mm. The active expansion phase typically takes 2-4 weeks, depending on how much widening is needed.
RPE works best in children whose mid-palatal suture has not yet fused, typically before age 14-15. It provides predictable skeletal expansion with minimal tooth tipping.
Slow Palatal Expander
A slow palatal expander uses smaller, less frequent turns (every other day or once every few days) to achieve the same widening over a longer period. Some orthodontists prefer this approach because it may produce more bone growth and less tooth tipping. The trade-off is a longer active expansion phase, typically 2-3 months. Slow expansion may cause less discomfort than rapid expansion.
Surgically-Assisted Rapid Palatal Expansion (SARPE)
In older adolescents and adults whose mid-palatal suture has fused, the bone is too rigid to separate with an expander alone. Surgically-assisted rapid palatal expansion involves a minor surgical procedure where an oral surgeon makes small cuts in the bone to weaken the suture before the expander is activated. This allows the expansion to proceed safely and predictably in patients who have finished growing.
SARPE is more involved than standard expansion and requires coordination between an orthodontist and an oral surgeon. Recovery from the surgical component is typically 1-2 weeks.
Removable Palatal Expanders
Some cases, particularly those needing only minor expansion, can be treated with a removable expander that looks similar to a retainer with a screw. Removable expanders are less predictable than fixed expanders because patient compliance determines the outcome. They are used less frequently and are generally reserved for mild cases or very young children.
How to Turn a Palatal Expander
Turning the expander is the parent's or patient's responsibility. Your orthodontist will provide a small key and demonstrate the technique at the bonding appointment. The process becomes routine within a few days.
To turn the expander, insert the key into the center hole of the screw mechanism. Push the key firmly from front to back until you see the next hole appear. Remove the key carefully by pulling straight down and back. Each full turn advances the screw by about 0.25mm. Your orthodontist will specify how many turns per day (usually one or two) and for how many days.
If you miss a turn, do not try to make up for it by doing extra turns the next day. Simply resume the normal schedule. If the key does not turn smoothly or you see something unusual, contact your orthodontist before proceeding.
What to Expect During Palatal Expansion
The expansion process follows a predictable pattern. Knowing what is normal helps parents and patients feel more confident throughout treatment.
Discomfort and Pressure
Most patients feel mild pressure across the roof of the mouth and around the nose for a few minutes after each turn. Some children describe it as a tingling or light headache that fades quickly. The first few turns tend to produce the most sensation. By the end of the first week, most patients report minimal discomfort with each turn.
Over-the-counter pain relievers can be used if needed, but most children do not require them regularly. If turning the expander causes sharp pain that does not subside, contact your orthodontist.
Gap Between the Front Teeth
As the upper jaw widens, a gap typically appears between the two upper front teeth. This gap is actually a positive sign. It means the expander is working and the bone is separating at the mid-palatal suture. The gap closes naturally over the following weeks and months as the teeth shift back together. If it does not close completely on its own, braces or aligners will close it during the next phase of orthodontic treatment.
Speech and Eating Adjustments
The expander sits on the roof of the mouth, which temporarily affects speech. Most patients have a slight lisp for the first few days as the tongue adjusts. Reading aloud and talking help the tongue adapt faster. Speech typically returns to normal within a week.
Eating requires some adjustment during the first few days. Soft foods are easier at first. Avoid sticky foods (caramel, taffy, gum) that can pull on the expander, and hard foods (nuts, hard candy, ice) that can damage it. Most patients return to a normal diet within a few days, with the exception of sticky and hard items.
Palatal Expander Timeline
The total time a palatal expander stays in the mouth is typically 6-12 months. This includes both the active expansion phase and the stabilization phase.
Active expansion (the turning phase) lasts 2-4 weeks. Once the desired width is reached, the orthodontist stops the turns but leaves the expander in place. This stabilization phase lasts 3-6 months and allows new bone to fill in the expanded suture. Removing the expander too early risks the jaw narrowing back to its original width.
After the expander is removed, most patients move into braces or aligners to align the teeth within the newly widened arch. The total orthodontic treatment, including the expansion phase, varies by case but often runs 18-30 months.
Age Considerations for Palatal Expansion
Age matters because the mid-palatal suture becomes progressively harder to separate as a person matures. In young children (ages 6-10), the suture is very flexible and expansion is straightforward. In adolescents (ages 11-14), expansion is still possible but may meet more resistance. By the late teens and into adulthood, the suture has typically fused, and conventional expansion without surgery is no longer reliable.
The American Association of Orthodontists recommends an initial orthodontic evaluation by age 7. Early evaluation allows the orthodontist to identify jaw width problems before the suture begins to fuse and recommend expansion at the optimal time.
For adults who need palatal expansion, surgically-assisted rapid palatal expansion (SARPE) or, in some cases, miniscrew-assisted rapid palatal expansion (MARPE) may be options. These approaches bypass the fused suture and can achieve skeletal expansion in older patients.
Palatal Expander Cost and Insurance
A palatal expander typically costs $1,000 to $3,000 when provided as a standalone appliance. This includes the custom fabrication, placement, all adjustment appointments, and removal. If the expander is part of a larger orthodontic treatment plan that includes braces, the cost is often bundled into the total orthodontic fee, which typically ranges from $3,000 to $7,000.
Dental insurance plans that include orthodontic benefits usually cover a portion of the expander cost when it is part of orthodontic treatment. Coverage varies by plan, but many pay 50% of orthodontic fees up to a lifetime maximum (commonly $1,000-$2,000). Surgically-assisted expansion may be partially covered under medical insurance if it is deemed medically necessary.
Many orthodontic offices offer interest-free payment plans that spread the cost over the duration of treatment. Costs vary by location and provider.
When to See an Orthodontist
If your child's dentist has mentioned a narrow palate, crossbite, or significant crowding, an orthodontic evaluation is the logical next step. Orthodontists are dental specialists with 2-3 years of residency training beyond dental school, focused entirely on tooth movement and jaw growth.
An orthodontist can determine whether a palatal expander is needed, recommend the best timing based on your child's growth stage, and plan the complete course of treatment. Early evaluation (around age 7) gives the orthodontist the most options for interceptive treatment. Learn more on our orthodontics specialty page.
Find an Orthodontist Near You
Every orthodontist on My Specialty Dentist has verified specialty credentials. Search by location to find orthodontists in your area who can evaluate whether your child needs a palatal expander.
Search Orthodontists in Your Area