[1] Univ Michigan, Dept Otolaryngol Head & Neck Surg, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Sch Med, Ann Arbor, MI USA
[3] Univ Michigan, Dept Pediat & Communicable Dis, Ann Arbor, MI 48109 USA
[4] Univ Michigan, Dept Obstet & Gynecol, Ann Arbor, MI 48109 USA
[5] Univ Michigan, Dept Surg, Ann Arbor, MI 48109 USA