1. Department of Otorhinolaryngology-Head and Neck Surgery, Inha University Hospital, Inha University School of Medicine, 27, Inhang-ro, Jung-gu, Incheon 22332, Republic of Korea
2. Department of Otorhinolaryngology, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, 20, Ilsan-ro, Wonju 26426, Republic of Korea
3. Department of Otorhinolaryngology-Head and Neck Surgery, Konkuk University School of Medicine, 120-1, Neungdong-ro, Gwangjin-gu, Seoul 05030, Republic of Korea
4. Department of Otorhinolaryngology-Head and Neck Surgery, Soonchunhyang University College of Medicine, Bucheon Hospital, 170, Jomaru-ro, Bucheon 14584, Republic of Korea