1 Department of Otorhinolaryngology-Head & Neck Surgery, Kyung Hee University Hospital, Kyung Hee University College of Medicine, Seoul, Republic of Korea.
2 Department of Otolaryngology-Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA.
3 Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul, Republic of Korea.