What Are the Grades of Microtia?
Understanding the severity of microtia helps guide treatment. Here is a description of each grade.
Microtia is classified into four grades based on the degree of ear development. The classification guides treatment decisions.
- Grade 1 Microtia:
- The ear is slightly smaller than normal
- All normal ear structures are present (helix, antihelix, lobule)
- The ear canal (external auditory canal) is usually present
- Hearing may be normal or only mildly affected
- Treatment: Often no treatment needed; reconstruction is optional for cosmetic reasons
- Grade 2 Microtia:
- The ear is partially formed and smaller than normal
- Some structures are present (usually the lobule and some cartilage)
- The ear canal is usually absent (atresia)
- Moderate conductive hearing loss
- Treatment: Surgical reconstruction recommended
- Grade 3 Microtia (most common, about 60% of cases):
- Only a small, peanut-shaped remnant of ear tissue is present
- No normal ear structure
- The ear canal is absent
- Moderate to severe conductive hearing loss
- Treatment: Ear reconstruction (rib graft or Medpor) + hearing aid (BAHA)
- Grade 4 Microtia (Anotia):
- Complete absence of the external ear
- Only a small dimple or no tissue at all
- Ear canal is absent
- Moderate to severe conductive hearing loss
- Treatment: Ear reconstruction + hearing aid
Additional Classification
- Unilateral microtia β affects one ear (more common)
- Bilateral microtia β affects both ears (less common, requires more intensive hearing management)
Clinical Guidance
Microtia grades range from 1 (mild, almost normal ear) to 4 (complete absence). Grade 3 (peanut-shaped remnant) is the most common. Treatment depends on the grade and includes ear reconstruction and hearing aids for most cases.