MARPE (Miniscrew-Assisted Rapid Palatal Expansion) is an orthodontic method in which the expansion appliance is anchored directly to the bone with small titanium screws placed in the palate. With conventional appliances, force is transferred to the bone through the teeth; after puberty, as the suture in the middle of the palate (the midpalatal suture) fuses, this force tips the teeth outward instead of separating the bone. MARPE aims to open the suture without a surgical operation by transmitting the force more directly to the bone. It can achieve skeletal expansion in late adolescents and young adults; however, this does not happen in every patient. The likelihood of success varies with age, the maturity of the suture and the bone structure; if the suture does not open, the plan is changed. For this reason, MARPE is an option, not a promise.
How is MARPE different from conventional expansion and surgery?
There are three basic approaches to a narrow upper jaw. Which one is appropriate depends on the amount of narrowing, age and the patient's expectations:
Comparison of upper jaw expansion approaches
| Feature | Conventional fixed appliance | MARPE | Surgically assisted (SARPE) |
|---|---|---|---|
| Where the force is transferred | Through the teeth | Directly to the bone via miniscrews (also to the teeth in some designs) | To bone weakened by surgical cuts |
| Period of common use | Growing children and early adolescents | Late adolescents and young adults | Adults, especially with severe narrowing |
| Procedure | Fitted with bands | Screw placement under local anesthesia | Surgical procedure under general anesthesia or deep sedation |
| Main limitation | Mostly tips the teeth when the suture is fused | The suture does not open in every patient | Surgical recovery period and surgical risks |
This is a general framework. The appropriate method is determined after examination and imaging.
We explained the general framework of expansion options for adults in our article on jaw expansion in adults. If you are curious about the other purposes miniscrews are used for in orthodontics, see our article on miniscrews (TADs). This page focuses on the MARPE decision, the process and its limits.
Who is MARPE considered for, and who might it not suit?
MARPE comes into consideration for patients in whom the narrowing has been confirmed to be truly skeletal. When the teeth are only tipped inward, simpler methods may be sufficient.
Situations that may be evaluated
- Unilateral or bilateral posterior crossbite caused by skeletal narrowing of the upper jaw
- Late adolescents in whom the suture is not expected to open with a conventional fixed appliance
- Young adults with mild or moderate narrowing and no plan for jaw surgery
- Patients who need skeletal expansion before orthodontic treatment to prevent the teeth from tipping too far outward
Situations that may not be suitable or that require caution
- Palatal bone that is not thick enough for miniscrews
- Untreated gum disease or inadequate oral hygiene
- Use of medications that affect bone metabolism (for example, bisphosphonates) or uncontrolled systemic diseases; these must be mentioned at the examination
- Cases that require a very large amount of expansion or have a marked discrepancy in the front-to-back relationship of the jaws; in these patients, planning together with jaw surgery may be more predictable
- Corrections requiring marked asymmetry
Is there an age limit for MARPE?
There is no accepted definitive upper age limit. Scientific publications show that the likelihood of the suture opening is higher in young adults, decreases with age, and that results vary markedly from person to person. However, a significant share of these studies were carried out in small patient groups, with different appliance designs and different activation protocols. For this reason, it would not be right to give a percentage-based expectation of success for a specific age. Two people of the same age can differ in the degree of suture fusion, bone density and palatal thickness. In the evaluation, the suture structure and bone thickness seen on three-dimensional imaging (CBCT) are a better guide than chronological age.
How does MARPE treatment progress?
- Evaluation: The amount of narrowing, the state of the suture and the bone thickness at the screw sites are examined through an examination, an intraoral scan, photographs and CBCT.
- Planning: Screw positions and appliance design are determined. The appliance is custom-made; most designs use four miniscrews.
- Placement: The miniscrews are placed in the palate under local anesthesia and the appliance is secured. The procedure is usually completed in one session; some sensitivity may be felt for a few days afterward.
- Activation: The appliance's screw is turned according to a schedule set by the orthodontist. This period lasts a few weeks, with frequent checkups. When the suture opens, a gap appears between the upper front teeth; this is an expected sign that the bone has separated.
- Holding period: After the target width is reached, the appliance stays in place passively for a few months while bone is expected to form in the opened area.
- Removal of the appliance and screws: Removing the screws is usually a short, simple procedure; the screw sites generally heal within a few days.
- Orthodontic treatment and retention: In most patients, treatment continues with braces or clear aligners to align the teeth. You can find how the next stage is planned for adults on the Invisalign for adults page. At the end of treatment, a retention appliance is used to maintain the width.
What are the risks and limits of MARPE?
Although MARPE is a less invasive option than surgically assisted expansion, it is not risk-free. It is important to know the following possibilities before deciding:
- The suture not opening: The bone may not separate despite activation. In this case, activation is stopped and the plan is reassessed.
- Asymmetric opening: The suture may open more on one side than the other.
- Miniscrew problems: Screws may loosen, rarely break or need to be placed again.
- Soft tissue irritation: Redness, inflammation or sores may develop in the palatal mucosa around the screws; cleaning reduces this risk.
- Pressure and pain: During activation, pressure may be felt at the bridge of the nose, the cheekbone area and the teeth, and some patients experience headaches.
- Dental side effects: Some of the force may still be transmitted to the teeth; outward tipping of the teeth and, in patients with thin gums, gum recession may occur.
- Temporary difficulties in daily life: In the first days, changes in speech, food getting trapped under the appliance and difficulty cleaning are common.
- Re-narrowing: If the retention phase is not followed, part of the width gained may be lost.
What happens if the suture does not open?
This possibility of failure should be discussed before treatment begins. Options include surgically assisted expansion (SARPE), partial dental compensation for the narrowing, or comprehensive planning together with jaw surgery. Which one is appropriate depends on the amount of narrowing and the patient's preference.
Is MARPE done for nasal breathing or snoring?
Some studies have reported widening of the floor of the nasal cavity and changes in airway measurements after palatal expansion. However, this effect differs from person to person and does not always match the breathing comfort the patient feels. MARPE is not a stand-alone treatment for sleep apnea or snoring. These complaints are diagnosed by a sleep medicine specialist and an ear, nose and throat physician. Recommending MARPE solely to improve breathing to a patient who does not need expansion from an orthodontic standpoint is not a sound approach.
How is daily life affected during the activation and holding periods?
Because the appliance covers most of the palate, some sounds may change in the first days while the tongue gets used to the new space; in most patients this decreases noticeably within a week or two. During this period, soft foods in small bites should be preferred, and hard, sticky foods and chewing gum should be avoided. The mouth should be rinsed with water after every meal, and food trapped between the appliance and the palate should be cleaned with a water flosser or a soft brush. Keeping the tissue around the screws clean is the most important step in reducing the risk of inflammation. For working patients, timing the first days of activation for a period without meetings that require a lot of talking can be practical planning.
What questions should you ask before deciding?
- Is my narrowing skeletal, or is it caused by the teeth being tipped?
- What does the imaging show about the state of the suture and the palatal bone?
- If the suture does not open, what alternatives are in the plan?
- Which orthodontic stage is planned after expansion, and how long is the total duration expected to be?
- Does my gum structure carry a risk with outward movement of the teeth?
- How often will I need to come for checkups during activation?
You can find out to what extent orthodontic treatment can change the skeletal structure on this page, and all expansion methods on the jaw expansion treatment page.
How is MARPE evaluated at the clinic?
At Funda Sarıkaya Oral and Dental Health Polyclinic, jaw narrowing in adult patients is evaluated by Funda Pekyılmaz Sarıkaya, specialist orthodontist (Uzm. Dt.). At the examination, the type of narrowing, gum condition, general health information and expectations are considered together; three-dimensional imaging is requested if deemed necessary. If MARPE is not considered suitable, the reasons and alternatives are shared openly. The treatment plan and fee are provided in writing after the records have been evaluated.