Hemifacial hyperplasia

What it is

Hemifacial hyperplasia is a rare morphological anomaly of the maxillofacial region characterized by unilateral overgrowth of all facial structures (bone, soft tissues, teeth), called true hemifacial hypertrophy, or overgrowth of one or more but not all facial structures, called partial hemifacial hypertrophy. It may be isolated or related to some syndromes (e.g. Beckwith-Wiedemann, Proteus, Klippel-Trenaunay-Weber, McCune-Albright syndrome, Neurofibromatosis type 1). It may be associated with airway obstruction, sensorineural hearing loss or swallowing difficulties.

Key facts

Prevalence

1-9 / 100 000 (United States)

Age of onset

Antenatal, Infancy, Neonatal

Inheritance

Not applicable

Classified as

Malformation syndrome

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

Signs and symptoms

These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.

ICD-10 codes

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Cross-references