1. Department of Otorhinolaryngology, Chosun University Hospital, Gwangju, South Korea
2. Department of Otorhinolaryngology, Hanyang University Medical Center, Seoul, South Korea
3. Department of Otorhinolaryngology, Chungnam National University Hospital, Daejeon, South Korea
4. Department of Otorhinolaryngology, Samsung Medical Center, Seoul, South Korea
5. Department of Otorhinolaryngology, Pusan National University Yangsan Hospital, Yangsan, South Korea
6. Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, South Korea
7. Department of Otorhinolaryngology, Gangnam Severance Hospital, Seoul, South Korea
8. Department of Otorhinolaryngology, Wonju Christian Hospital, Wonju, South Korea
9. Department of Otorhinolaryngology, Kyunghee University Hospital, Seoul, South Korea
10. Department of Otorhinolaryngology, Yeungnam University Medical Center, Daegu, South Korea
11. Department of Otorhinolaryngology, Chonnam National University Hospital, Gwangju, South Korea
12. Department of Otorhinolaryngology, Keimyung University Dongsan Medical Center, Daegu, South Korea
13. Department of Otorhinolaryngology, Bucheon St. Mary's Hospital, Bucheon, South Korea
14. Department of Otorhinolaryngology, Wonkwang University Hospital, Iksan, South Korea
15. Department of Otorhinolaryngology, Severance Hospital, Seoul, South Korea
16. Department of Otorhinolaryngology, Seoul St. Mary's Hospital, Seoul, South Korea
17. Department of Otorhinolaryngology, Ajou University Medical Center, Suwon, South Korea
18. Department of Otorhinolaryngology, Kyunghee University Hospital at Gangdong, Seoul, South Korea
19. Department of Otorhinolaryngology, Pusan National University Hospital, Pusan, South Korea
20. Department of Otorhinolaryngology, Seoul National University Boramae Medical Center, Seoul, South Korea
21. Department of Otorhinolaryngology, Ulsan University Hospital, Ulsan, South Korea
22. Department of Otorhinolaryngology, Chungbuk National University Hospital, Cheongju, South Korea
23. Department of Otorhinolaryngology, Korea University Ansan Hospital, Ansan, South Korea
24. Department of Otorhinolaryngology, Dong-A Medical Center, Pusan, South Korea
25. GlaxoSmithKline Korea, Seoul, South Korea
26. Department of Otorhinolaryngology, Seoul National University Hospital, Seoul, South Korea