The Posterior Muscles of the Auricle: Anatomy and Surgical Applications

Objective: Prominent ears are generally considered as primary cartilage deformities, but some authors consider that posterior auricular muscles malposition could play a role in the genesis of this malformation. Study design: Auricle dissections of 30 cadavers and histologic sections of 2 fetuses’ ears. Methods: Posterior area of the auricle has been dissected in 24 cadavers preserved with zinc chlorure and 6 fresh cadavers in order to describe the posterior muscles and fascias of the auricle. Posterior auricle muscles from 5 fresh adult cadavers have been performed and two fetal auricles (12 and 22 weeks of amenorhea) have been semi-serially sectioned in horizontal plans. Five μm-thick sections were processed for routine histology (H&E) or for immuno histochemistry using antibodies specific for the slow-twitch and fast-twich myosin heavy chains in order to determine which was the nature of these muscles. Results: The posterior auricular and the transversus auriculae muscles looked in most cases like skeletal muscles and they were made of 75% of slow muscular fibres. The histologic sections of the auricle in the fetus suggest that the transversus auriculae plays a role in the constitution of the antihelical fold. The obliquus auriculae muscle was rather a fascia than a muscle in adult dissections and in fetuses auricle sections. Conclusion: Some cases of prominent ears are related to anomalies of the posterior muscles of the auricle.