1. Department of Otorhinolaryngology–Head and Neck Surgery, College of Medicine, Korea University, Seoul
2. Department of Otorhinolaryngology–Head and Neck Surgery, College of Medicine, Soonchunhyang University, Bucheon Hospital, Geonggyi-do
3. Department of Otorhinolaryngology–Head and Neck Surgery, College of Medicine, BunDang JeSaeng Hospital, Geonggyi-do, South Korea