[1] Drexel Univ, Coll Med, Philadelphia, PA 19129 USA
[2] Boston Univ, Dept Otolaryngol Head & Neck Surg, Med Ctr, Boston, MA 02118 USA
[3] Harvard Med Sch, Dept Otolaryngol Head & Neck Surg, Massachusetts Eye & Ear, Boston, MA 02114 USA
[4] Drexel Univ, Coll Med, 2900 W Queen Lane, Philadelphia, PA 19129 USA