Merck Manual

Please confirm that you are a health care professional

honeypot link

Mandibular Condylar Hyperplasia

By

Gary D. Klasser

, DMD, Louisiana State University School of Dentistry

Last full review/revision Jun 2020| Content last modified Jun 2020
Click here for Patient Education

Mandibular condylar hyperplasia is a disorder of unknown etiology characterized by persistent or accelerated growth of the condyle when growth should be slowing or ended. Growth eventually stops without treatment.

Slowly progressive unilateral enlargement of the head and neck of the condyle causes crossbite malocclusion, facial asymmetry, and shifting of the midpoint of the chin toward the unaffected side. The patient may appear prognathic. The lower border of the mandible is often convex on the affected side. Chondroma and osteochondroma may cause similar symptoms and signs, but they grow more rapidly and may cause even greater asymmetric condylar enlargement.

Diagnosis of Mandibular Condylar Hyperplasia

  • Plain x-rays

  • Usually cone beam CT

On plain x-rays, the temporomandibular joint may appear normal, or the condyle may be proportionally enlarged and the mandibular neck elongated. Cone beam CT is usually done to determine whether bone growth is generalized, which confirms the diagnosis, or localized to a particular part of the condyle. If growth is localized, a biopsy may be necessary to distinguish between tumor and hyperplasia.

Treatment of Mandibular Condylar Hyperplasia

  • During active growth, usually condylectomy

  • After growth cessation, orthodontics followed by surgical mandibular repositioning

Treatment usually includes condylectomy during the period of active growth. If growth has stopped, orthodontics and surgical mandibular repositioning are indicated. If the height of the mandibular body is greatly increased, facial symmetry can be further improved by reducing the inferior border of the mandible.

Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read

Test your knowledge

Tongue Discoloration and Other Changes
A 12-year-old girl is brought to the office by her grandmother because she has had pain in her mouth for the past week. The patient appears to be drooling. Physical examination shows a smooth red tongue. Tenderness is noted on palpation of the oral mucosa. Based on these findings, this patient most likely has a deficiency of which of the following? 
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
TOP