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Key Points
Second most common facial anomaly after cleft lip and palate.
Characteristic findings include hypoplasia of malar, maxillary, and/or mandibular regions of the face with associated anomalies of the ears and vertebrae.
Incidence is as high as 1 in 3,000-5,000 livebirths if mild cases are included.
Associated with eye, ear, vertebral, cardiac, renal, and urinary anomalies.
Karyotype is indicated.
Deliver infant in tertiary care center if polyhydramnios is present.
Perform complete audiologic evaluation on all infants postnatally.
Rule out syndromic causes.
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Hemifacial microsomia is the second most common facial anomaly after cleft lip and palate. It is a predominantly unilateral malformation of craniofacial structures that originally develop fromthe first and second branchial arches. The characteristic findings of hemifacial microsomia include hypoplasia of the malar, maxillary, and/or mandibular regions of the face with associated abnormalities of the ears and vertebrae (Burck, 1983). The term hemifacial microsomia was first used by Gorlin and Pindborg (1964), who described a condition consisting of unilateral microtia, macrostomia, and failure of formation of the mandibular ramus and condyle. Since then, hemifacial microsomia has been considered one phenotypic manifestation of a group of disorders that affect the face, ears, eyes, vertebrae, heart, and kidneys. This spectrumof disorders has been called “oculoauriculovertebral dysplasia,” although this is technically incorrect because the term dysplasia refers to abnormalities of cellular differentiation. An association between hemifacial microsomia, auricular malformations, and specific malformations of the eye known as epibulbar dermoids was first recognized by Goldenhar in 1952 (Heffez and Doku, 1984). Although the name Goldenhar syndrome is widely used, the use of the word syndrome is also incorrect because there is no known unique cause for this phenotype. At present, hemifacial microsomia is considered to be part of a complex developmental field defect known as the oculoauriculovertebral (OAV) anomaly. There is no agreement on the minimal diagnostic criteria and the phenotypic spectrum for this condition (Rollnick, 1988). It is not known whether OAV anomaly represents one entity with variability in the phenotype or whether there are several different entities with similar phenotypes. Causal heterogeneity for this group of conditions has been described (Rollnick, 1988). However, any fetus identified with asymmetry of the facial structures or hemifacial microsomia should be considered to be at risk for associated eye, ear, vertebral, cardiac, and renal malformations.
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The incidence of hemifacial microsomia varies considerably according to the minimal diagnostic criteria used to define the condition. When the most mildly affected individuals are included, the incidence is on the order of 1 in 3000 to 1 in 5000 livebirths (Benacerraf and Frigoletto, 1988). When only the most severely affected patients are included, the incidence was on the order of 1 in 45,000 livebirths in one study performed in Northern Ireland (Morrison et al., 1992). Approximately two-thirds ...