The anatomic components of hemifacial microsomia have been classified previ
ously, but their relevance to functional abnormalities has not been stresse
d. In a recent review of the literature, we found that the frequency and se
verity of airway disorders, especially those leading to upper airway obstru
ction and/or obstructive sleep apnea, had not been reported. Accordingly, a
retrospective study of 38 patients (21 male, 17 female), aged 6 months to
22 years (mean, 8 years 3 months) with hemifacial microsomia was undertaken
to ascertain the frequency and severity of airway disorders in hemifacial
microsomia. Upper airway disorders fell broadly within three categories: gr
oup I (n = 22, 58 percent) was asymptomatic for airway disturbances; group
II (n = 7, 18 percent) had a medical history suspect for intermittent obstr
uctive sleep apnea or had a perioperative apneic event; and group III (n =
9, 24 percent) had a definite history of obstructive sleep apnea or upper a
irway obstruction requiring tracheotomy or apnea surgery. Group III versus
groups II and I had a higher incidence of bilateral involvement (33 percent
versus 14 percent and none), a greater percentage of M2, M2a, M2b, and M3
mandibular deformities (88.9 percent versus 28.6 percent and 18.2 percent),
more severe orbital involvement (33 percent O2 and O3 versus none in group
II and 9 percent in group I), and more severe soft-tissue involvement (89
percent S2 and S3 versus 29 percent and 23 percent). Patients with more sev
ere mandibular and orbital deformities, but not ear or vertebral abnormalit
ies, appear at a greater risk for obstructive sleep apnea. The relationship
of OMENS-Plus (extracraniofacial anomalies) to apnea was variable but was
found more commonly in group II (86 percent) and group III (56 percent) tha
n in group I (32 percent) patients. Group III patients had a higher frequen
cy of cardiac anomalies (44 percent versus 29 percent in group II and 23 pe
rcent in group I). The incidence of obstructive sleep apnea in our populati
on of patients with hemifacial microsomia approaches 24 percent. Patients w
ith hemifacial microsomia should undergo routine screening for obstructive
sleep apnea: a positive history warrants polysomnographic and anatomic work
up.