1. Division of Rhinology and Sinus Surgery; Department of Otolaryngology-Head and Neck Surgery ; Medical University of South Carolina; Charleston; South Carolina; U.S.A
2. Rhinology and Sinus Surgery, Division of Otolaryngology; Department of Surgery ; University of Calgary; Calgary; Alberta; Canada
3. Department of Otolaryngology-Head and Neck Surgery ; Stanford University; Palo Alto; California; U.S.A
4. Division of Rhinology and Sinus Surgery , Oregon Sinus Center, Department of Otolaryngology-Head and Neck Surgery; Oregon Health and Science University; Portland; Oregon; U.S.A