1. Department of Otorhinolaryngology-Head and Neck Surgery; College of Medicine, Konkuk University; Seoul Korea
2. Department of Anatomy; Yonsei University College of Medicine; Seoul Korea
3. Department of Otorhinolaryngology; Yonsei University College of Medicine; Seoul Korea
4. Airway Mucus Institute; Yonsei University College of Medicine; Seoul Korea
5. BK21 Project for Medical Science, Yonsei University College of Medicine; Seoul Korea