Microtia

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Microtia

• Shankai Yin Prof
• Dept of Otolaryngology, the sixth hospital
  affiliated to Shanghai jiaotong university
• Otolaryngology institute at Shanghai jiaotong
  university

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Epidemiology

• Occurs 1 in 7,000 to 8,000 infants
• Occurs more often in right ears
• Occurs more often in males
• Higher incidence in Hispanics and Asians than in
  blacks and whites
• Fewer than 15 with positive family history
• Associated with other congenital malformations

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Etiology

• Known causes
• Thalidomide(?? )
• Isotretinoin()
• Genetic
• Risk factor
• Diabetes

The occurrence of microtia is usually a random,
sporadic event, and it is important for the
parents to understand that the deformity was not
caused by anything the mother did before or
during the pregnancy
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Embryology of Auricle

• From The Ear comprehensive otology

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Anatomy of auricle

• From The Ear comprehensive otology

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Classification of Microtia

• Many classification systems
• Grade I, II, III
• Grade I all anatomic subunits present but
  misshapen
• Grade II anatomic subunits either deficient or
  absent
• Grade III classic peanut ear and anotia

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• Grade I A slightly small ear with identifiable
  structures and a small but present external ear
  canal
• Grade II A partial or hemi-ear with a closed off
  or stenotic external ear canal producing a
  conductive hearing loss
• Grade III Absence of the external ear with a
  small peanut vestige structure and an absence of
  the external ear canal and ear drum
• Grade IV Absence of the total ear or anotia

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Microtia reconstruction
History

• Dr. Tanzer 1959
• 1st article on auricular reconstruction with
  autogenous rib cartilage, 6 stages procedure
• Dr. Brent 1974
• 4 stages procedure, foremost authority on
  auricular reconstruction
• Dr. Nagata 1985
• 2 stages procedure

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Principles

• Hearing
• testing is first done to determine if the inner
  ear is intact and hearing is normal.
• External canal
• to determine if a canal exists, by CT scan. (if a
  canal is not visible externally)
• Age
• The earliest age surgery can be attempted is age
  3 for Medpor and 6 for Rib Cartilage Grafts.
  However a later age recommend, 8-10 when the ear
  is full adult size.

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Surgery options

• canal reconstruction
• Ear canal reconstruction is unnecessary and
  overcomplicated
• Very good hearing is possible with modern hearing
  aids
• auricular reconstruction
• Rib Cartilage Graft Reconstruction
• a polyethylene plastic implant

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Rib Cartilage Graft
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The ear frame before it is assembled
a polyethylene plastic
Ear frame assembly
Photo of implant components on a surgical drape.
Caution The porous implant material should not
be placed on surgical drapes or other fibrous
material that may shed particles on the implant.
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Long term result
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Tissue engineering