Palatal Expansion for Adults — MARPE and BASME/DOME

A narrow upper arch can contribute to a range of functional and aesthetic problems, including:

• Dental crowding
• Posterior crossbite (where the upper back teeth bite inside the lower teeth)
• Breathing difficulties and nasal airway obstruction
• Sleep-disordered breathing, including obstructive sleep apnoea
• Compensated bites that have developed to accommodate a narrow upper jaw
• The need for arch width correction before or after orthognathic surgery

Identifying the right treatment approach requires a thorough assessment, including 3D imaging (CBCT) to evaluate the degree of suture fusion, bone density, and available skeletal anatomy.

MARPE is a non-surgical technique designed for skeletally mature patients where the midpalatal suture is partially fused but capable of being separated with adequate force.

How it works

A bone-anchored palatal expander is secured to the palate using four small titanium miniscrews (temporary anchorage devices). Because the forces are applied directly to bone rather than through the teeth, MARPE can achieve genuine skeletal expansion of the upper jaw — widening the nasal base, expanding the dental arch, and improving nasal airway volume — without the need for surgery.

Activation

The expander is activated by turning a small key, typically once or twice per day for a defined period. The suture is gradually separated, and new bone forms in the space created.

Who is suitable

MARPE is most effective in adults up to the mid-30s, where CBCT imaging confirms partial suture patency. It is not effective once the suture is fully ossified — in those cases, BASME or DOME is required.

Benefits

• No surgery required
• Genuine skeletal expansion (not dental tipping)
• Improvements in nasal breathing frequently reported
• Proven beneficial in sleep-disordered breathing when used as part of a broader treatment plan

BASME (Bone-Anchored Slow Maxillary Expansion) is an advanced approach used when MARPE is not sufficient — typically where the midpalatal suture is more fully fused or where a greater degree of expansion is required. What distinguishes BASME from conventional rapid expansion techniques is the rate at which expansion is delivered: by expanding slowly and incrementally, the technique works not only by separating the suture but by harnessing the biological process of distraction osteogenesis — known in this context as DOME (Distraction Osteogenesis Maxillary Expansion).

How it works

A bone-anchored device is placed to deliver controlled, gradual expansion forces directly to the palatal bone. At the slow activation rates used in BASME, the separation of bone triggers the formation of new bone in the expanding gap — the same principle that underlies distraction osteogenesis in other parts of the skeleton. Rather than forcing a rapid split of the suture (which creates significant strain on surrounding structures), the tissue is given time to respond and regenerate progressively. The result is genuine skeletal expansion accompanied by healthy bone formation in the distraction zone.

Why this approach reduces side effects and discomfort

Rapid palatal expansion in adults — even with bone anchorage — can produce unwanted effects: soft tissue trauma, significant discomfort during activation, and an increased risk of relapse if the expanded bone is not given adequate time to consolidate. BASME addresses these issues directly. The slower activation rate distributes forces more gradually, reducing the strain on surrounding bone and soft tissue. Patients typically report significantly less discomfort during the expansion phase compared to rapid expansion protocols. The quality of the bone formed through distraction osteogenesis also supports long-term stability of the result.

Who is suitable

BASME/DOME is appropriate for any adult over the age of 20 where rapid expansion is not desirable. This includes patients where a slower, more controlled expansion process is preferred to make treatment more comfortable, reduce the risk of side effects, and minimise potential complications. It is also the approach of choice for those requiring greater arch expansion, those with a more fully fused suture, and patients undergoing expansion as part of a broader airway management or orthognathic treatment plan.

Coordination of care

This treatment is planned and delivered in close collaboration with oral and maxillofacial surgical colleagues where surgical involvement is required for device placement. Treatment planning, activation protocols, and consolidation timelines are agreed collaboratively to achieve the planned expansion safely and effectively.