1. Department of Otorhinolaryngology-Head and Neck Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
2. Department of Pathology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
3. Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Ansan, Korea
4. Department of Otorhinolaryngology-Head and Neck Surgery, Gyeongsang National University School of Medicine, Jinju, Korea