High Arch Palate and Orthodontics: Causes, Concerns, and Treatment Options

What is a high arch palate?

The palate is the bony roof of the mouth, separating the oral cavity from the nasal cavity. A normal palate has a moderate arch height and sufficient width to accommodate the upper teeth in a well-aligned arc. A high arch palate — also termed a gothic palate — is one where the palatal vault is unusually tall and the arch is narrow. This often means the upper dental arch is too narrow to accommodate the permanent teeth without crowding, and the relationship between the upper and lower dental arches may be compromised. The condition exists on a spectrum from mild (minimal clinical impact) to severe (significant crowding, crossbite, and nasal airway restriction).

What causes a high arch palate?

A high arch palate can have several causes, which often interact. Genetic predisposition is the most common factor — jaw shape and size are largely inherited. Early oral habits during the critical growth years can also play a significant role: prolonged thumb sucking, dummy (pacifier) use beyond age 3 to 4, and tongue thrusting can alter the pressure balance in the developing upper arch, producing a narrow, high-arched result. Mouth breathing is both a cause and a consequence — children who breathe predominantly through the mouth rather than the nose fail to benefit from the tongue resting on the palate (which provides a natural expansion force), and the resulting lack of pressure allows the palate to narrow and rise. Conditions causing nasal obstruction — allergic rhinitis, enlarged adenoids, or nasal polyps — can initiate or worsen mouth breathing and contribute to palatal narrowing over time.

How it affects bite and nasal airway

A narrow palate typically produces crowding of the upper front teeth, as there is insufficient arch length to accommodate them. It frequently causes a posterior crossbite — where one or more upper back teeth sit inside the lower back teeth rather than outside them, reversing the normal biting relationship. In more severe cases, a unilateral crossbite can cause the lower jaw to shift to one side when biting, creating a functional asymmetry. The narrowed palate also reduces the floor area of the nasal cavity, which sits directly above. This reduces nasal airway volume and can contribute to nasal obstruction, mouth breathing, snoring, and in some cases obstructive sleep apnoea — particularly in children, where the proportional impact on the airway is greater. Restoring palatal width can improve nasal airflow as well as dental alignment.

When is treatment needed for a high arch palate?

Not every high arch palate requires orthodontic treatment. Intervention is indicated when there is a posterior crossbite causing a functional jaw shift, significant crowding that cannot be accommodated as permanent teeth erupt, evidence of airway restriction attributed to palatal narrowing, or where expansion is needed to create space before fixed appliance treatment. An orthodontist will assess the arch width, occlusion, airway history, and dental development before recommending expansion. In children, the optimal time for expansion is during active growth — when the mid-palatal suture (the join between the two halves of the upper jaw) has not yet fused. This suture typically begins to close in the mid-teens, making early intervention more effective and less complex.

Palatal expansion in children — rapid maxillary expansion (RME)

Rapid maxillary expansion (RME) is the standard treatment for a narrow palate in growing children. An RME appliance — also called a palate expander — is a fixed device cemented to the upper back teeth, spanning the palate. It contains a jackscrew that parents turn daily or twice daily using a small key, gradually widening the device and applying lateral force to the two halves of the upper jaw. Over a period of 2 to 4 weeks, the mid-palatal suture is gradually opened, new bone forms in the gap, and the upper arch becomes wider. The appliance is then left passive for 3 to 6 months while the new bone consolidates. RME is most effective in children under 14 to 15, before the mid-palatal suture begins to fuse. After the expansion phase, fixed braces are typically used to align the teeth in the wider arch.

Adult options — SARPE and alternative approaches

In adults over 16 to 18 whose mid-palatal suture has fused, non-surgical palatal expansion produces tooth tipping rather than true skeletal expansion, and can cause periodontal complications including fenestration and recession of bone over the roots of the teeth being moved. SARPE — Surgically Assisted Rapid Palatal Expansion — is the recommended approach for adults requiring significant skeletal expansion. It involves a minor surgical procedure carried out under general anaesthetic to release the mid-palatal suture and the surrounding bony buttresses, after which a palatal expander is activated in the same way as for children. The surgical release allows true bony expansion to occur without the complications of non-surgical attempts on a fused suture. SARPE is carried out jointly by an orthodontist and an oral and maxillofacial surgeon, and is available on the NHS in appropriate cases.

What expansion treatment involves

Palatal expansion treatment — whether RME in children or SARPE in adults — involves several stages. Records are taken before treatment including digital scans or impressions, radiographs, and photographs. The appliance is fitted under local anaesthetic (for RME) or following surgery (for SARPE). Activation instructions are given to parents or the patient — typically one to two turns per day. A gap often appears between the upper front teeth during expansion as the palatal suture widens; this is normal and closes spontaneously after activation stops. After the expansion phase, the appliance is left passive for consolidation. Fixed appliances are usually fitted after the expander is removed to align the teeth. Retention after expansion is important to prevent relapse.

Airway and breathing improvements

A growing body of evidence links palatal expansion with measurable improvements in nasal airway volume and nasal breathing. Studies using CBCT imaging have demonstrated increases in nasal cavity cross-sectional area following RME in children, with associated reductions in nasal resistance and improvements in nasal flow. Parents often report improved sleep, reduced snoring, and fewer mouth-breathing episodes in children following expansion. The improvements in nasal airflow are generally more significant in children than in adults, as the relationship between palatal width and nasal cavity dimensions is more direct before the mid-palatal suture fuses. Where a child has sleep-disordered breathing related to a narrow upper airway, early palatal expansion may reduce the severity of the problem and potentially delay or prevent the need for surgical intervention.

Long-term retention after expansion

Palatal expansion is subject to relapse — the teeth and jaw have a tendency to return towards their original width after treatment ends. Long-term retention is therefore essential. Following RME or SARPE, a fixed or removable retention appliance is used to hold the expansion while bony consolidation occurs. After fixed appliances are removed, a transpalatal arch or bonded lingual retainer may be used to maintain arch width. Patients should be counselled that retention is a long-term commitment — removing retainers prematurely increases the risk of the arch narrowing again. Regular review appointments allow the orthodontist to monitor arch width and retainer fit over time.

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.