1. Department of Otolaryngology, Ajou University School of Medicine, Suwon 16499, Republic of Korea
2. Department of Medical Sciences, Ajou University Graduate School of Medicine, Suwon 16499, Republic of Korea
3. Department of Otorhinolaryngology, Konyang University College of Medicine, Daejeon 35365, Republic of Korea
4. Department of Otorhinolaryngology-Head and Neck Surgery, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul 07441, Republic of Korea