Clarifying the Relationships among the Different Features of the OMENS+ Classification in Craniofacial Microsomia

Background: The OMENS+ classification is commonly used to describe the phenotypically diverse craniofacial features of craniofacial microsomia. The purpose of this study was to evaluate associations among the individual components of the OMENS+ criteria. Methods: An institutional review board–approved retrospective chart review was performed for patients who presented with a diagnosis of unilateral or bilateral craniofacial microsomia to the craniofacial clinic from January of 1990 to December of 2012. Demographic, diagnosis, classification, treatment, and radiographic data were abstracted for all patients who met inclusion criteria. Associations and correlations were evaluated using the Spearman rank test and a logistic regression model. Results: One hundred five patients (61 male and 44 female) with craniofacial microsomia met inclusion criteria. Eighty-one patients (77.1 percent) had unilateral microsomia and 24 (22.9 percent) had bilateral microsomia. Twenty-eight patients (26.7 percent) had macrostomia. Correlations were all significantly interrelated (p = 0.000 to p = 00.018) between the degree of orbital, mandibular, and soft-tissue deformities. Moreover, the severity of ear deformity and facial nerve involvement were also significantly correlated (p = 0.008). Between these two groupings, there was a significant correlation between soft-tissue deficiency and nerve involvement (p = 0.010). Macrostomia was associated with the individual components of the group orbit (p = 0.008), mandible (p = 0.000), and soft tissue (p = 0.005). Conclusions: The association between structures using the OMENS+ classification may be caused by their branchial arch origin. Structures mainly developed from the first branchial arch (orbit, mandible, and soft tissue) are associated in degree of severity, as are the structures mainly derived from the second branchial arch (facial nerve and ear). CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.