Microtia refers to a small pinna of the ear. when is it completely absent it is terms anotia.
The estimated incidence at around 1 : 9000 live births. It is commoner in males and there is a recognised right sided predilection.
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
It is classified into four grades based on increasing severity
- grade I : slightly small ear with identifiable structures ; external auditary canal small but present
- grade II: partial or hemi-ear with a occluded or stenotic external ear canal producing a conductive hearing loss
- grade III : absence of the external ear with a small peanut like vestige structure and an absence of the external ear canal and ear drum
- grade IV : complete absence (anotia).
- 1 Mayer TE, Brueckmann H, Siegert R et-al. High-resolution CT of the temporal bone in dysplasia of the auricle and external auditory canal. AJNR Am J Neuroradiol. 1997;18 (1): 53-65. AJNR Am J Neuroradiol (abstract) - Pubmed citation
- 2. Swartz JD, Faerber EN. Congenital malformations of the external and middle ear: high-resolution CT findings of surgical import. AJR Am J Roentgenol. 1985;144 (3): 501-6. AJR Am J Roentgenol (abstract) - Pubmed citation
- 3. Calzolari F, Garani G, Sensi A et-al. Clinical and radiological evaluation in children with microtia. Br J Audiol. 1999;33 (5): 303-12. - Pubmed citation
- 4. Takegoshi H, Kaga K, Kikuchi S et-al. Facial canal anatomy in patients with microtia: evaluation of the temporal bones with thin-section CT. Radiology. 2002;225 (3): 852-8. doi:10.1148/radiol.2253010942 - Pubmed citation
- 5. Lemmerling M, Kollias SS. Radiology of the petrous bone. Springer Verlag. (2004) ISBN:354042394X. Read it at Google Books - Find it at Amazon
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