Ear projection and the posterior auricular muscle insertion.

Prominent ears is a common congenital anomaly affecting approximately 5 percent of the general population. The etiology has been attributed to three basic deformities in the ear structure: valgus of the concha with a cranioauricular angle greater than 40 degrees, underfolding of the anthelix, and rarely, hypertrophy of the concha. It is believed that by virtue of its insertion onto the ponticulus, the cranial surface of the concha, the posterior auricular muscle may function to pull the auricle back toward the head. A proximally (anteromedially) displaced insertion site would decrease the length of the effective momentum of the muscle, leading to protrusion of the auricle. This study was conducted to determine if indeed a relationship between the posterior muscle insertion site and ear projection could be established clinically by measuring these parameters intraoperatively in patients presenting for otoplasty and in patients without prominent ears who required conchal cartilage grafts for other procedures.