[1] George Washington Univ, Childrens Natl Med Ctr, Dept Otolaryngol, Sch Med & Hlth Sci, Washington, DC USA
[2] Western Univ, London Hlth Sci Ctr, Dept Otolaryngol Head & Neck Surg, London, ON, Canada
[3] Western Univ, Schulich Sch Med & Dent, London, ON, Canada
[4] Virginia Hosp Ctr, Dept Obstet & Gynecol, Arlington, VA USA
[5] Boston Univ, Boston Med Ctr, Dept Otolaryngol Head & Neck Surg, Chobanian & Avedisian Sch Med, Boston, MA USA
[6] Childrens Natl Med Ctr, Dept Otolaryngol, 111 Michigan Ave NW, Washington, DC 20010 USA