What anatomical area does hemifacial microsomia most often impact?

Hemifacial microsomia is a congenital condition characterized by underdevelopment of one side of the face, most frequently affecting the ears and mandible. This condition results from disruptions in the development of the first and second pharyngeal arches during embryogenesis, leading to asymmetric facial features.

The mandible is often notably affected, with patients displaying a smaller or absent ramus and a more retruded chin on the affected side. Additionally, ear anomalies are common, such as microtia (underdeveloped ear) or anotia (absence of ear). These characteristics highlight the mesodermal contributions of the arches to structures in the lower face and ears, making the ears and mandible the central focus of this condition.

Understanding the correct area impacted by hemifacial microsomia is crucial for planning management and surgical intervention for affected individuals, as it guides the treatment of associated functional and aesthetic complications.