In 1952, Maurice Goldenhar published a case collection of congenital mandibulofacial malformations with or without epibulbar dermoids, auricular appendages and
With the attempt to systematically classify these malformations, he described for the first time what later became known as the Goldenhar syndrome. Goldenhar syndrome is grouped within the spectrum of craniofacial microsomia. It consists of hemifacial microsomia (HFM), epibulbar dermoids and vertebral anomalies. Major manifestations of HFM are orbital distortion, mandibular hypoplasia, ear anomalies, nerve involvement and soft tissue deficiency (OMENS). In addition, patients with Goldenhar syndrome can present with heart, kidney and lung malformations as well as spine and limb deformities. Depending on the organs affected and the severity of the malformations, the phenotype is highly variable. The OMENS-Plus classification system is most commonly used to describe the phenotype variability of craniofacial microsomia (Amendment 1). The exact cause of Goldenhar syndrome is unknown but considered to be multifactorial, i.e., a combination of gene interactions and environmental factors that causes a maldevelopment of the first and the second branchial arch during the first trimester of pregnancy. Males are affected more often than females (3:2). About 10–30 % of patients have bilateral, usually asymmetric facial microsomia. There is no agreement on the incidence of Goldenhar syndrome in the literature. Reports vary between 1:3,000–5,000 and 1:25,000–40,000. A recent population-based data linkage study of the epidemiology of rare craniofacial abnormalities in Western Australia found a birth prevalence of 15.8 (11.6–20.9) per 100,000
live and stillbirths in the decade from 2000 to 2010. This study found associations between maternal hypothyroidism and craniofacial microsomia. Craniofacial microsomia was also
associated with twin or higher order multiples as compared to singleton births and with preterm births, low birth weight and low Apgar scores. The relevance of these associations
has yet to be determined.