Uezono et al evaluated children with congenital microtia for risk factors associated with difficult intubation. These can help identify a child who should have a more extensive examination prior to anesthesia and additional precautions taken. The authors are from Chiba, Japan and Boston Children's Hospital.


Patient selection: Children with unilateral or bilateral microtia (hypoplasia of the auricle)


Risk factors from the OMENS classification (orbit, mandible, ear, nerve, soft tissue) of hemifacial microsomia (HFM):

(1) asymmetrical size and/or position of orbit

(2) small mandible and/or abnormal ramus or condyle on X-ray

(3) facial nerve weakness

(4) soft tissue deficiency


number of risk factors =

= SUM(number of risk factors present)



• minimum number of risk factors (in addition to microtia): 0

• maximum number of risk factors: 4

• Children with bilateral microtia were more likely to have a difficult airway than those with unilateral microtia.

• The difficulty in visualizing the glottis increased with the number of abnormalities present.


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