1. Department of Otorhinolaryngology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Republic of Korea
2. Department of Otorhinolaryngology-Head and Neck Surgery, Incheon St.Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
3. Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Republic of Korea