1. Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University College of Medicine, Seoul, Korea.
2. Department of Otorhinolaryngology-Head and Neck Surgery, Chosun University College of Medicine, Gwang-ju, Korea.
3. Department of Otorhinolaryngology-Head and Neck Surgery, Pusan National University College of Medicine, Pusan, Korea.
4. Department of Otorhinolaryngology-Head and Neck Surgery, Soon Chun Hyang University College of Medicine, Seoul, Korea.
5. Research Center for Sensory Organs, Seoul National University College of Medicine, Seoul, Korea.