Hyperdontia and Supernumerary Teeth: Orthodontic Treatment in the UK

What is hyperdontia?

Hyperdontia is the developmental condition in which one or more supernumerary teeth — teeth that exceed the normal number of 20 primary or 32 permanent teeth — are present. It affects approximately 1 to 3% of the population in the permanent dentition and around 0.5% of primary dentitions. Supernumerary teeth may be single or multiple, erupt into the mouth or remain impacted within the jaw, and occur in isolation or as part of a syndrome such as cleidocranial dysplasia or Gardner syndrome. The majority are found in the upper jaw, and most require some form of management.

Types of supernumerary teeth

Supernumerary teeth are classified by position and morphology. A mesiodens sits in the midline between the upper central incisors and is the most common type, making up approximately 50% of all supernumeraries. It is often cone-shaped or tuberculate and is frequently impacted. Paramolars are extra teeth positioned buccally or palatally adjacent to the upper molars. Distomolars, also called fourth molars or distodens, are positioned distal to the upper third molars. Supplemental teeth closely resemble the tooth they are adjacent to — most often a lateral incisor — and may be harder to identify on X-ray. By shape, supernumeraries can be conical (pointed), tuberculate (barrel-shaped with multiple cusps), supplemental (normal shape), or odontome-like (disorganised hard tissue mass).

How common is hyperdontia?

Studies report prevalence of supernumerary teeth in the permanent dentition at between 0.1 and 3.8%, with the majority of studies clustering around 1 to 2%. Males are affected approximately twice as often as females. The upper anterior region accounts for around 90% of cases. Multiple supernumeraries are more likely to occur in association with syndromes; isolated multiple supernumeraries without a syndrome are uncommon but do occur. In primary dentitions the condition is less common and is often managed more conservatively than in the permanent dentition.

How supernumerary teeth are detected

Many supernumeraries are detected incidentally on dental X-rays taken for other purposes. A dental panoramic tomograph (DPT or OPG) provides an overview of the whole dentition and jaws and will show most impacted supernumeraries, though distortion and superimposition can obscure exact position. Where a supernumerary is suspected near important structures — particularly close to the roots of adjacent incisors or deeply impacted — cone beam CT (CBCT) provides three-dimensional information that allows precise localisation before surgery. Clinically, erupted supernumeraries may be visible in the mouth or cause crowding, but impacted ones are often asymptomatic and discovered only on imaging.

Effects on adjacent teeth

Supernumerary teeth can cause a wide range of problems. Crowding is one of the most frequent — the extra tooth displaces the normal teeth out of their correct position, leading to rotations, ectopic eruption, or failure to erupt. A mesiodens between the upper centrals is a classic cause of a midline diastema. Eruption delay or complete failure to erupt occurs when a supernumerary physically blocks the path of an adjacent permanent tooth — most often affecting the upper central incisors, which are then described as retained or unerupted. Root resorption of adjacent teeth can occur if the supernumerary is in close proximity and exerts pressure, which is one reason early detection and intervention are important. Cyst formation around an impacted supernumerary is a less common but clinically significant complication.

When should a supernumerary tooth be removed?

The timing of supernumerary removal is debated. Early removal in children avoids prolonged blockage of permanent teeth and can allow spontaneous eruption, but early surgery in young children carries its own risks including damage to developing tooth buds. The general guidance is that when a supernumerary is causing or likely to cause a problem — delayed eruption of an adjacent tooth, crowding, diastema, or resorption — removal is indicated. When a supernumerary is inverted and high in the palate with no apparent effect on adjacent teeth, it may be monitored rather than removed. Timing is usually planned in coordination with the orthodontist to maximise the benefit of surgical removal and minimise the overall treatment time.

Surgical removal techniques

Removal of an erupted supernumerary is straightforward and is similar to any dental extraction. Impacted supernumeraries require a surgical approach: a mucoperiosteal flap is raised, bone is removed to expose the tooth, the tooth is delivered, and the site is sutured. Where a supernumerary is palatally impacted and the adjacent permanent tooth is also impacted, the surgeon may attach a gold chain or bracket to the permanent tooth at the same time — a technique called surgical exposure and bonding — to allow the orthodontist to apply traction to guide the tooth into the arch. The procedure is most commonly performed under local anaesthetic and intravenous sedation, or under general anaesthetic in younger children.

Orthodontic treatment after extraction

Following supernumerary removal, several outcomes are possible. If the adjacent permanent tooth erupts spontaneously into a satisfactory position, orthodontic treatment may be limited to alignment and space management. More commonly, some active orthodontic treatment is needed: closing a diastema caused by the mesiodens, uprighting a displaced tooth, or applying traction to an unerupted tooth that has been surgically exposed. Treatment is usually with fixed braces, and the duration depends on the degree of displacement and the time taken for the tooth to respond to traction. Periodic review is important because root resorption of adjacent teeth can occur during treatment, particularly if orthodontic forces are applied to teeth in close proximity to the extraction site.

NHS vs private treatment

Supernumerary tooth removal that is causing or is likely to cause clinical problems qualifies for NHS treatment in children under 18 in England, provided the patient is registered with an NHS dentist or referred to a community dental service or hospital. The high IOTN scores that often accompany unerupted teeth blocked by supernumeraries mean orthodontic treatment is also frequently NHS-eligible. For adults, NHS coverage depends on clinical need, and some straightforward cases may fall outside eligibility. Private treatment offers faster access to diagnosis, CBCT imaging, and joint surgical-orthodontic planning, and is often preferred by patients seeking to minimise the overall timeline.

Long-term monitoring

After supernumerary removal and orthodontic treatment, long-term monitoring is important. Adjacent teeth that were in contact with the supernumerary should be watched for signs of root resorption and pulp changes on subsequent radiographs. The orthodontic retention phase must be maintained, particularly where a diastema was closed, as there is a tendency for spacing to recur, especially if the labial frenum was not assessed and treated where indicated. In patients with multiple supernumeraries or an associated syndrome, ongoing dental surveillance is recommended as further supernumeraries can develop.

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.