[1] Univ Calgary, Dept Surg, Div Otolaryngol Head & Neck Surg, Calgary, AB T2N 2T9, Canada
[2] Med Univ S Carolina, Div Rhinol & Sinus Surg, Dept Otolaryngol Head & Neck Surg, Charleston, SC 29425 USA
[3] Univ New S Wales, Appl Med Res Ctr, St Vincents Hosp, Sydney, NSW, Australia
[4] Macquarie Univ, Sydney, NSW 2109, Australia
[5] Loyola Univ, Med Ctr, Dept Otolaryngol Head & Neck Surg, Maywood, IL 60153 USA
[6] Royal Natl Throat Nose & Ear Hosp, Profess Unit, London WC1X 8DA, England
[7] Oregon Hlth & Sci Univ, Dept Otolaryngol Head & Neck Surg, Div Rhinol & Sinus Surg, Portland, OR 97201 USA