Palatal Expander for Adults UK

Why standard palatal expanders do not work in adults

In children and adolescents, the two halves of the hard palate are separated by a cartilaginous midpalatal suture. Orthodontic expansion appliances such as the rapid palatal expander (RPE) or Hyrax apply lateral force across this suture, gradually separating the two palatal shelves and allowing new bone to fill the gap — a process called sutural expansion. By approximately the mid-twenties, this suture undergoes synostosis: the cartilage calcifies and the two bony halves fuse. Once fused, the same lateral force applied by a conventional expander can no longer separate the palatal shelves; instead it tips or bends the alveolar bone and causes dental rather than skeletal expansion. This produces a temporary widening effect that is prone to rapid relapse and does not produce the true arch width increase needed to correct a skeletal narrow palate in an adult.

SARPE — surgically-assisted rapid palatal expansion

Surgically-assisted rapid palatal expansion (SARPE) is the most widely used surgical method for skeletal palate expansion in adults in the UK. The procedure is performed under general anaesthetic by an oral and maxillofacial surgeon (OMFS), typically within an NHS or private hospital setting. The surgeon makes controlled osteotomy cuts through the hard palate and around the pterygoid plates to release the midpalatal suture and separate the maxilla from surrounding bony attachments. A conventional palatal expansion appliance — usually a tooth-borne or tissue-borne Hyrax screw — is bonded to the upper teeth before surgery and is activated afterwards during the healing period. This combination of surgical release and gradual appliance activation achieves true skeletal expansion. The surgery typically takes one to two hours, and patients are usually discharged the same day or after one night in hospital.

SARPE recovery and activation protocol

Following SARPE, patients typically experience swelling, some bruising, and mild to moderate discomfort for the first week. Most return to normal activities within two weeks, though strenuous exercise is avoided for four to six weeks. The expansion appliance is activated by the patient using a small key, usually with one to two quarter-turns per day — each quarter-turn produces approximately 0.25mm of expansion. The total active expansion phase typically lasts four to eight weeks, depending on the amount of skeletal width increase required. Following active expansion, the appliance is left in place passively for three to six months to allow new bone to consolidate in the expanded suture. During this consolidation phase, orthodontic treatment with braces or aligners is typically started to align the teeth within the newly expanded arch.

MSE — miniscrew-assisted skeletal expander

The miniscrew-assisted skeletal expander (MSE), also known as the bone-borne palatal expander or microimplant-assisted rapid palatal expansion (MARPE), is a less invasive alternative to SARPE that has gained significant clinical attention in the UK over the past decade. The MSE device consists of a palatal expansion screw connected to four or more titanium miniscrews (temporary anchorage devices or TADs) that are placed directly into the palatal bone through the gingiva under local anaesthetic. Because the force is delivered to the bone via the TADs rather than through the teeth, the expansion force bypasses dental tipping and acts directly on the midpalatal suture. Clinical studies have shown that MSE can successfully open the midpalatal suture in adults up to their mid-thirties and occasionally beyond, with CT imaging used to confirm suture opening.

How MSE works and who is suitable

MSE activation follows a similar protocol to SARPE, with daily quarter-turns producing gradual lateral force. The key difference is that no surgery or hospital admission is required — the procedure is carried out entirely in a specialist orthodontic practice or hospital outpatient setting. Suitability for MSE depends on the degree of suture fusion (assessed on CBCT imaging), the patient's age, the amount of expansion required, and palatal bone thickness and quality. Patients in their late twenties to early to mid-thirties with partial suture fusion are the best candidates. Heavily fused sutures in older adults may not open with MSE forces alone, and SARPE remains the more reliable option for complete skeletal expansion in these cases. MSE is generally considered lower risk than SARPE, with the main side effects being temporary soreness around the TAD insertion sites and the diastema (gap between the upper front teeth) that opens during expansion and closes with subsequent orthodontic treatment.

Outcomes — how much expansion is achievable

Both SARPE and MSE can achieve significant skeletal arch width increases. In most cases, 8 to 12mm of total expansion is achievable, though the clinically stable amount retained after consolidation and orthodontic settling is typically slightly less. True skeletal expansion means that the width gained reflects actual bone and arch development rather than dental tipping, which makes it more stable long-term. Following expansion, fixed orthodontic treatment or clear aligner therapy is required to align the teeth within the new arch width, close any diastema created during expansion, and achieve the final occlusion. The entire treatment journey from expansion through orthodontic alignment typically takes two to three years in adults.

Retention after palatal expansion

Following completion of active expansion and orthodontic treatment, retention of arch width is maintained using a transpalatal arch (TPA) — a rigid wire connecting the upper first molars across the palate — or a bonded palatal retainer. Some clinicians also use the expansion appliance itself as a passive retainer during the consolidation phase. Long-term, the expanded arch width needs to be held by retainers for at least two years, and many clinicians recommend indefinite retention. Clear aligners used as retainers provide some arch support, but they should be supplemented with a rigid palatal retainer to prevent the arch from narrowing. Patients should be counselled that the expansion result is stable only if proper retention is maintained.

NHS vs private costs for SARPE in the UK

SARPE may be available on the NHS when palatal expansion is part of a combined orthodontic-surgical treatment plan for a significant functional malocclusion. NHS commissioning criteria for orthognathic surgery in England require an IOTN score of 5 and the presence of a functional impairment, meaning that purely cosmetic cases will not qualify. Where NHS treatment is approved, the surgery and associated orthodontic treatment are covered, though waiting times can be lengthy — often one to three years in some regions. Private SARPE in the UK typically costs between £4,000 and £8,000 for the surgical component alone, with orthodontic treatment adding a further £3,000 to £6,000. MSE as a private procedure generally costs less than SARPE overall, as no surgical facility or general anaesthetic is required, with total costs including orthodontics typically in the range of £5,000 to £9,000.

Useful related pages

This guide is for general information only. It is not a diagnosis, treatment plan, or substitute for advice from a registered dentist or orthodontist.