1 Department of Otorhinolaryngology-Head and Neck Surgery, Yongin Severance Hospital, Yonsei University College of Medicine, 363, Dongbaekjukjeon-Daero, Giheung-Gu, Yongin-Si Gyeonggi-Do, Republic of Korea. hilguy@yuhs.ac.
2 Department of Otorhinolaryngology-Head and Neck Surgery, Yonsei Head and Neck Cancer Center, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.