Microtia

Last revised by Frank Gaillard on 27 Mar 2024

Microtia refers to a small pinna of the ear, when is it completely absent it is termed anotia.

Epidemiology

The estimated incidence at around 1:9000 live births. It is more common in males and there is a recognized right sided predilection.

Pathology

Associations

Microtia can be associated with a wide spectrum of inner and middle ear anomalies 1. Isolated microtia is relatively uncommon. The most frequent associations include: 

Wider organ associations include:

Syndromic associations include:

Classification

A number of classification of microtia have been described 6-10. The classification proposed by Weerda in 1998 9, which is built upon earlier classifications by Marx 10, Rogers and Tanzer, is probably most widely used, and divides microtia into three grades based on increasing severity 9:

  • first degree (Marx grade I)

    • slightly smaller ear than normal (>2 SD below mean)

    • all structure are identifiable and essentially normal

  • second degree (Marx grade II)

    • small l (>2 SD below mean)

    • some features are abnormal while other are recognizable

  • third degree (Marx grade III)

    • absence of the external ear with a small deformed vestigial structure with no recognisable features.

    • often associated with external acoutic canal atresia

  • anotia (sometimes referred to as grade IV) 7

    • complete absence of the external ear (anotia)

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.