1. Department of Otolaryngology, Masan Samsung Hospital, School of Medicine, Sungkyunkwan University, Masan, Korea.
2. Department of Otorhinolaryngology and Head & Neck Surgery, College of Medicine, KyungHee University, Seoul, Korea.
3. Department of Otorhinolaryngology and Head & Neck Surgery, School of Medicine, Eulji University, Seoul, Korea.
4. Bio ENT Clinics, Gwangju, Korea.