Medically reviewed by Dr. Amin P. Samadian, DDS, MBA, Diplomate of the American Board of Dental Sleep Medicine and Fellow of the American Academy of Craniofacial Pain. Last reviewed November 7, 2026.
For a long time an adult with a narrow upper jaw was told there were two choices: tip the teeth outward with braces, or have jaw surgery. MARPE is a third option. It widens the upper jaw itself, in the bone, and for many adults it does that without an operation. Dr. Amin Samadian plans and places MARPE expanders at the San Francisco Center for TMJ and Sleep Apnea. Call 415-570-2841 to ask whether you are a candidate.
What MARPE is
MARPE stands for miniscrew-assisted rapid palatal expansion. The upper jaw is made of two halves that meet along a seam in the middle of the palate. In children that seam is still flexible, which is why a regular expander works well for kids. By adulthood the seam has matured, and a regular expander mostly tips the teeth instead of moving the bone.
A MARPE expander is held by four small miniscrews placed in the roof of the mouth. Because the force goes into the bone rather than the teeth, the two halves of the upper jaw can be separated and widened. New bone then fills the space. The Maxillary Skeletal Expander (MSE) we use is one MARPE design.
Who we see for MARPE
- Adults with a narrow, high palate and crowded upper teeth
- Adults with a crossbite where the upper back teeth sit inside the lower ones
- People who breathe through their mouth, snore, or have a small nasal airway and want the upper jaw evaluated as part of the picture
- TMJ patients whose bite pushes the lower jaw back or to one side
- Adults who were told surgery was the only way to widen the jaw
Age alone does not decide it. How mature the palate seam is, how thick the bone is, and what the gums and teeth look like are what matter, and those are read on a 3D scan.
How treatment goes
- Consultation and CBCT scan. We take a 3D cone beam scan of the jaws and airway in the office. It shows the palate seam, the bone where the miniscrews will go, and the size of the nasal passage.
- A custom expander. The appliance is designed from your scan and digital impressions, so the miniscrew positions are planned before the visit.
- Placement. The expander is fitted and the miniscrews are placed with local anesthetic at one appointment.
- Activation at home. You turn the expander a small amount on a set schedule. We see you regularly during this phase. A space opening between the two front teeth is the expected sign that the jaw is widening.
- Holding phase. Once the width is reached, the expander stays in place while new bone forms.
- Finishing. The expander comes out and the teeth are aligned with clear aligners or clear braces, then held with a retainer.
Why the airway is part of the conversation
The floor of the nose is the roof of the mouth. When the upper jaw is widened, the nasal floor widens with it, and the tongue gets more room to rest up against the palate instead of falling back toward the throat. That is why we look at breathing, snoring and sleep along with the bite. If sleep apnea is suspected, we arrange a home sleep study so the plan is based on a measurement rather than a guess. How much any one person's breathing changes varies, and we talk through what your scan shows before you decide.
MARPE, regular expanders and surgery
A regular tooth-borne expander is the right tool for a growing child, and we use it for kids through our pediatric expansion and ALF care. For an adult it mostly moves teeth. Surgically assisted expansion (SARPE) cuts the bone to release it and is done in a hospital setting. MARPE sits between the two. Some adults, usually with very mature or very thick palates, are still better served by the surgical route, and the scan tells us which group you are in.
Book a MARPE consultation in San Francisco
We are at 260 Stockton St, 4th Floor, San Francisco, CA 94108. Call 415-570-2841 or request an appointment online.
