Analysis of the Posterior Auricular Muscle

The posterior auricular muscle is a small skeletal muscle arising from the mastoid process and inserting onto the eminentia conchae. Many species utilize the auricular muscles to adjust the pinna to better localize sounds. In humans, the muscle is vestigial and consequently its morphological features are not well characterized in the literature. Advances in plastic surgery have identified the potential utility of this muscle in improving the outcomes of otoplasty procedures. Data from 99 left and right posterior auricular muscles from 50 formalin-fixed whole-body donors were collected. Muscle length and width were measured with digital calipers and the number of tendinous insertions was noted. Additionally, information about donor height and age at death were gathered. Descriptive statistics were calculated along with statistical tests evaluating group differences and relationships between variables. For all muscles studied, the mean muscle width and length were 8.75 mm and 27.50 mm, respectively. Most muscles (73.7%) had a single tendinous insertion, 23.2% had two distinct muscular slips inserting at unique locations, and three muscles had a triple insertion onto the concha (3.0%). The results of these findings enhance the current knowledge of the posterior auricular muscle’s characteristics, including those salient during otoplasty procedures.