Topics in Oral Medicine
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Hyperdontia

From the DentTest dentistry textbook, with 10 practice questions. Last updated 6 August 2026.

Clinical case

A 9-year-old child attends because the upper left central incisor has not erupted. The contralateral incisor erupted one year ago. Examination shows a retained primary incisor and a small midline diastema. Radiographs show a conical supernumerary tooth obstructing the eruption path.

Pathophysiology

Hyperdontia is thought to result from excessive or abnormal proliferation of the dental lamina. The additional tooth may develop as a simple conical structure or as a more organised tooth resembling the normal dental series.

Supernumerary teeth are particularly important because they can obstruct eruption, displace adjacent teeth and cause crowding.

Epidemiology and Risk Factors

Non-modifiable

Modifiable

Family history

No modifiable risks factors

Male sex

Cleidocranial dysplasia

Cleft lip and palate

Clinical Features

Hyperdontia is the presence of additional teeth beyond the normal dental complement. These additional teeth are called supernumerary teeth. A supernumerary tooth may be simple and conical or may resemble a normal tooth.

A supplemental tooth is a supernumerary tooth with normal morphology.

Symptoms

Signs

Delayed eruption

Labial, buccal or palatal eruption

Extra erupted tooth

Midline diastema

Crowding

Retained primary tooth

Poor aesthetics

Displacement or rotation

Investigations

Primary investigations:

  • Full medical and dental history

  • Clinical examination

  • Radiographs: OPG to assess number, position and associated impaction; periapical for more localised assessment; upper occlusal radiographs can be useful for anterior maxillary supernumerary teeth

Gold standard investigation:

Diagnosis is based on clinical and radiographic identification of additional teeth.

Investigations to consider:

  • Cone beam CT for complex localisation and surgical planning

  • Orthodontic assessment

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