Vascular pathogenesis of unilateral craniofacial defects.

The term hemifacial microsomia refers to unilateral defects in development of structures derived from the first and second branchial arches. Recently we evaluated three unrelated children who had a similar pattern of unilateral craniofacial defects that was associated with other structural abnormalities having a disruptive vascular pathogenesis. The clinical findings in these patients suggest that one cause of hemifacial microsomia is in utero interruption of blood flow.