Article Overview
- MARPE, MARPE-Zero, MASPE, MSE, FME… What Do All These Names Mean?
- What Is MARPE?
- Our Modern MARPE/MASPE Protocol
- Why the Lower Arch Matters
- Why Slow Expansion?
- What Is a Custom MARPE?
- The Design Process: Prefabricated MARPE vs. Custom 3D-Printed MARPE
- Planning Beyond Expansion
- Why We Design and Deliver Our Own MARPE Appliances
- Should Myofunctional Therapy Come Before or After MARPE?
- How Much Does MARPE Improve Nasal Breathing?
- How Are the Spaces Closed After Expansion?
- Strategy 1: Retract the Front Teeth
- Strategy 2: Bring the Molars Forward
- Strategy 3: Restorative Closure
- Are Newer “Bandless” MARPE Designs Better?
- Why Close Monitoring Is Essential
- Why Experience Matters
MARPE Quick Facts
- Most adults can be candidates for non-surgical MARPE.
- MARPE expands the upper jaw by opening the midpalatal suture.
- Modern protocols combine slow expansion with Invisalign.
- Most patients experience a very small or nearly invisible front tooth gap.
- Expansion may improve nasal breathing in many patients.
- Successful treatment depends heavily on appliance design and provider experience.
1. MARPE, MARPE-Zero, MASPE, MSE, FME… What Do All These Names Mean?
If you’ve been researching adult palatal expansion, you’ve probably come across a confusing list of names: MARPE, MARPE-Zero, MASPE, MSE, FME, and many others. It can feel like every orthodontist has invented a new acronym.
The good news is that these names do not represent completely different treatments and the umbrella term for all this is MARPE.
Some refer to a specific expander design, while others describe a particular treatment philosophy or expansion protocol. Although the names differ, they all share the same objective: creating true skeletal expansion by opening the midpalatal suture without jaw surgery.
The differences primarily involve:
- Whether the expansion screw is prefabricated or custom designed (3D printed) for each patient.
- Whether expansion follows a rapid or slow protocol. The “R” in MARPE stands for Rapid, whereas the “S” in MASPE stands for Slow, reflecting the rate at which the palate is expanded.
- Whether Invisalign or braces begin before, during, or after expansion.
- Whether treatment intentionally creates a large visible gap (diastema) between the front teeth or minimizes it.
- Whether additional features—such as facemask arms, intrusion hooks, or other attachments—are incorporated into the appliance to support later stages of orthodontic treatment.
Each of these design decisions influences not only the expansion itself but also the efficiency, comfort, esthetics, and long-term stability of treatment.
At ClearWave Orthodontics, every MARPE appliance is a custom 3D-printed appliance tailored to each patient’s unique palatal anatomy, bone volume, and bone thickness. We utilize a slow expansion protocol synchronized with Invisalign treatment, allowing skeletal expansion and tooth movement to occur simultaneously while minimizing a gap between the front teeth (diastema).
2. What Is MARPE?
MARPE (Miniscrew-Assisted Rapid Palatal Expansion) is an orthodontic appliance designed specifically for adolescents and adults whose palatal suture has matured.
Unlike child palatal expanders that anchor only on the teeth, MARPE uses precisely positioned titanium miniscrews called Temporary Anchorage Devices (TADs) that anchor directly into the palatal bone. Throughout this article, we’ll use the term TADs to distinguish them from the expansion screw located in the center of the appliance.
Because the force is delivered directly to the underlying bone rather than primarily through the teeth, MARPE can separate the midpalatal suture and widen the upper jaw itself in older teens and adults.
Expanding the palate can help:
- Correct posterior crossbites and improve the bite.
- Create space for crowded teeth.
- Upright flared front teeth.
- Increase the volume of the oral cavity and the tongue space.
- Increase the volume of the nasal cavity, which can improve nasal airflow and breathing in many patients.
Because the roof of the mouth also forms the floor of the nose, widening the palate increases the volume of the nasal cavity. For many patients, this results in easier nasal breathing during sleep, exercise, and daily activities. However, breathing is influenced by many other factors, including turbinate enlargement, septal deviation, allergies, nasal valve anatomy, and overall airway health. As a result, many adults seeking palatal expansion have already undergone allergy treatment, turbinate reduction, septoplasty, or other ENT procedures but continue to experience chronic nasal congestion.
While MARPE is not a substitute for medical or ENT treatment, it can structurally increase the volume of the nasal cavity, potentially improving nasal airflow by addressing the underlying skeletal anatomy. In our clinical experience, the majority of patients who undergo MARPE expansion report significant improvement in their ability to breathe through their nose.
3. Our Modern MARPE/MASPE Protocol
At ClearWave Orthodontics, our treatment philosophy combines many of the advances introduced by today’s modern MARPE protocols, including concepts found in MARPE-Zero, MASPE, and other contemporary approaches. Dr. Jinny has been performing MARPE for over 13 years, currently initiating 5-10 MARPE therapies each week, at over 98% success rate.
Rather than the traditional way of performing rapid expansion first and correcting the teeth by braces or Invisalign afterward, we synchronize skeletal expansion with Invisalign treatment from the beginning.
Our protocol begins with a brief period of expansion—typically over a week or two—until we confirm successful opening of the midpalatal suture. Our goal is to create only a very small diastema (gap) of approximately 0.5 mm between the upper front teeth. This confirms that the suture has opened while minimizing any cosmetic concerns. At that point, Invisalign treatment begins.
Once the patient receives their Invisalign aligners, MARPE expansion and Invisalign progress simultaneously in a carefully synchronized manner. In our office, we commonly use the Tiger Power Screw, one of the most widely used expansion screws for Custom MARPE. One surface-turn of the screw produces approximately 0.17 mm of expansion. The Invisalign treatment is digitally programmed to match this exact amount of skeletal expansion. Every five days, the patient:
- Changes to the next Invisalign aligner
- Performs one surface-turn of the MARPE expander
As a result, the teeth and the upper jaw expand together at the same rate. This synchronized approach minimizes undesired gap opening while maintaining excellent control over the developing bite. At the same time, treatment is designed to coordinate expansion of the lower arch.
4. Why the Lower Arch Matters
One aspect of treatment that is often overlooked is the lower jaw.
Many adults with a narrow upper jaw also have lower molars that have gradually tipped inward toward the tongue in an attempt to meet the upper molars in the narrower jaw bone.
If only the upper jaw is expanded, the orthodontist may eventually have to tip the upper teeth inward simply to fit the still-constricted lower arch. This can reduce smile fullness and decrease tongue space.
In addition, the amount of upper expansion is ultimately limited by the width of the lower arch, as the upper molars cannot be positioned significantly farther outward than the lower molars while maintaining a functional bite.
Unlike the upper jaw, the lower jaw does not have a suture that can be expanded. Instead, treatment focuses on uprighting the lower posterior teeth to broaden the lower arch. Depending on the patient, this may be accomplished with:
- Invisalign combined with cross elastics attached to lingual buttons, or
- A lower expansion appliance that gradually uprights the lower molars.
Both methods are effective, and the choice depends on each patient’s anatomy, periodontal health, treatment goals, and lifestyle.
By treating both arches together, we can often achieve a broader, more stable bite while preserving tongue space and smile aesthetics.
5. Why Slow Expansion?
Traditional MARPE protocols emphasized rapid expansion, creating a large gap between the front teeth before orthodontic treatment began.
Modern protocols like the MASPE protocol, favor slow, controlled skeletal expansion synchronized with orthodontic treatment.
This slower approach offers several advantages:
- A much smaller—or often nearly invisible—gap between the front teeth
- Greater patient comfort
- More controlled skeletal adaptation
- Reduced mechanical stress on surrounding facial structures
- Better preservation of the gum tissue (interdental papilla) between the upper front teeth
- Improved smile aesthetics throughout treatment
- Better control of the final tooth positions without unnecessarily retracting the upper front teeth
For many adult patients, these advantages make the treatment process both more comfortable and more aesthetically pleasing.
6. What Is a Custom MARPE?
One of the biggest recent advances in adult palatal expansion is the development of the Custom 3D-Printed MARPE, which is digitally designed for each patient’s unique anatomy and fabricated using high-precision 3D metal printing.
Rather than adapting a stock appliance to the patient, the appliance is designed around the patient’s CBCT scan, digital models, and treatment objectives.
6a) The Design Process: Prefabricated MARPE vs. Custom 3D-Printed MARPE
Prefabricated MARPE systems are an excellent option for many patients with relatively wider palates and favorable anatomy. They utilize an expansion screw with fixed dimensions, so the appliance must be designed around where the screw can physically fit within the palate.
With a Custom 3D-Printed MARPE, the design process begins by analyzing the CBCT scan to identify the optimal locations for the Temporary Anchorage Devices (TADs) based on bone thickness, bone volume, and bone quality. Once the TAD positions are determined, a compact Tiger Power Screw is positioned accordingly, and the remaining framework is custom designed and fabricated using 3D metal printing. This workflow allows greater flexibility to optimize TAD placement, expansion screw positioning, appliance angulation, and the incorporation of additional features that support the next phases of orthodontic treatment.
6b) Planning Beyond Expansion
MARPE is only the first step of treatment. Because the appliance is custom designed from the beginning, it can be tailored to facilitate the orthodontic movements that follow expansion.
For example:
- Correcting skeletal canting: If one side of the upper jaw is positioned lower than the other, the appliance can be designed with an angulation to partially correct the cant during expansion. The remaining correction is then completed during orthodontic treatment, reducing the amount of dental compensation required.
- Supporting gummy smile correction: Patients with excessive gum display may benefit from built-in hooks that later support molar intrusion using TADs.
- Facilitating molar mesialization: If the treatment plan calls for moving the back teeth forward instead of retracting the front teeth, facemask arms can be incorporated into the appliance from the outset.
These features cannot simply be added after expansion—they must be planned and incorporated before the appliance is fabricated.
7. Why We Design and Deliver Our Own MARPE Appliances
Some orthodontic offices refer patients elsewhere for MARPE fabrication or placement, and have the patients come back for orthodontic treatment.
At ClearWave Orthodontics, we design, fabricate, and deliver our own MARPE appliances because the appliance is only one part of the complete orthodontic treatment plan. Every design decision affects the next phase of treatment.
Because our team performs both the skeletal expansion and the orthodontic treatment, we can customize the appliance to support the entire treatment sequence—from expansion through finishing—rather than treating MARPE as a separate procedure.
8. Should Myofunctional Therapy Come Before or After MARPE?
This is one of the most common questions we receive. For both children and adults, we generally recommend beginning myofunctional therapy after expansion has been completed and the expander has been removed.
The goal of myofunctional therapy is to train the tongue to rest and function correctly against the palate. If therapy is started before expansion, the tongue is being trained to adapt to a narrow palate rather than the wider palate that treatment is intended to create.
In addition, while the MARPE appliance is in place, much of the palate is physically covered, making proper tongue positioning difficult. By waiting until expansion is complete, the tongue can be trained to function naturally within its new, wider environment.
9. How Much MARPE Expansion Improves Nasal Breathing?
One of the most common reasons adults seek MARPE is to improve nasal breathing.
Although every patient is different and improvement cannot be guaranteed, experienced MARPE providers generally agree that approximately 4–6 mm of skeletal expansion is often associated with a noticeable improvement in nasal breathing, based on patient-reported outcomes.
At ClearWave Orthodontics, many patients achieve 7 mm or more of expansion, even without an initial posterior crossbite. Patients with complete posterior crossbites may require—and are often able to achieve—12 mm or more of skeletal expansion.
The degree of improvement in nasal breathing varies from patient to patient and depends on many factors beyond the width of the palate, including turbinate size, septal deviation, allergies, nasal valve anatomy, and overall airway health. Because airway health is multifactorial, we frequently collaborate with ENT physicians and sleep physicians to evaluate and address these additional factors.
For patients with signs or symptoms of sleep-disordered breathing or diagnosed obstructive sleep apnea (OSA), we perform FDA-cleared home sleep testing before and after palatal expansion to objectively assess changes in sleep quality and breathing. The data helps the communication with collaborating physicians as well.
10. How Are the Spaces Closed After Expansion?
As the upper jaw widens during MARPE treatment, additional space naturally develops between the teeth because the jaw becomes larger while the teeth remain the same size. These spaces are then strategically managed as part of the orthodontic treatment plan.
Strategy 1: Retract the Front Teeth
The most traditional approach is to move the front teeth backward to close the spaces.
Strategy 2: Bring the Molars Forward
Another option is to move the back teeth forward instead of retracting the front teeth. This approach preserves tongue space and often produces fuller smile support, but it may require facemask arms to be incorporated into the MARPE appliance before treatment begins.
Strategy 3: Restorative Closure
In selected patients, the orthodontist may intentionally distribute small spaces between several teeth and have the restorative dentist close them with veneers or crowns to improve tooth proportions and smile esthetics.
The ideal strategy depends on facial profile, tongue space, periodontal health, restorative needs, and overall treatment objectives.
11. Are the Newer “Bandless” MARPE Designs Better?
Some so-called “newer” MARPE designs eliminate the molar bands entirely and rely only on the expansion screw attached to the palate.
While this concept may appear simpler, it is not new. It was explored extensively during the early development of MARPE in the early 2000s and has since been revisited by several experienced providers.
One important biomechanical consideration is that all expansion screws experience a small amount of twisting and distortion under heavy expansion forces. When molar bands are present, they help stabilize the appliance and distribute these forces.
Without that additional support, excessive distortion may reduce expansion efficiency and can increase the risk of asymmetric expansion, patient discomfort, or appliance failure. For this reason, our preference is to use designs that provide rigid support throughout the expansion process.
12. Why Close Monitoring Is Essential
MARPE is a highly technique-sensitive procedure and requires close monitoring throughout treatment.
At ClearWave Orthodontics, most patients submit photographs of their smile, teeth, and palate from home every 1-2 weeks, depending on their individualized expansion protocol.
These photographs allow our orthodontists to closely evaluate expansion progress, appliance stability, tissue health, and tooth movement. Adjustments can be made promptly, allowing treatment to proceed safely and predictably.
13. Why Experience Matters
Adult skeletal expansion has evolved rapidly over the past several years, and successful treatment depends on much more than simply placing an expander.
It requires careful diagnosis, digital treatment planning, coordination of skeletal expansion with orthodontic tooth movement, management of the lower arch, and close monitoring throughout treatment.
At ClearWave Orthodontics, we perform 5–10 MARPE procedures every week, placing us among the highest-volume providers of adult skeletal expansion. Dr. Jinny Kwak lectures nationally on advanced MARPE techniques, collaborates with many of the leading innovators in the field, and teaches orthodontic residents at the university level.
Choosing an experienced provider helps maximize the success of MARPE expansion and the likelihood of achieving a stable bite, improved nasal breathing and airway function, and an esthetic smile while minimizing complications throughout treatment.