1. Department of Otolaryngology–Head and Neck Surgery, Cancer Research Institute, Research Institute for Medical Sciences, Chungnam National University College of Medicine, Daejeon, Republic of Korea
2. Department of Otolaryngology, International St Mary’s Hospital, Incheon, Republic of Korea
3. Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Republic of Korea
4. Department of Otolaryngology, Ajou University School of Medicine, Suwon, Republic of Korea