1. Department of Otorhinolaryngology-Head and Neck Surgery, Hallym University College of Medicine, Chuncheon, Korea.
2. Department of Pediatrics, Pusan National University School of Medicine, Busan, Korea.
3. Soree Ear Clinic, Seoul, Korea.
4. Department of Otorhinolaryngology-Head and Neck Surgery, Inha University College of Medicine, Incheon, Korea.
5. Department of Otorhinolaryngology-Head and Neck Surgery, The Catholic University of Korea College of Medicine, Seoul, Korea.
6. Department of Otorhinolaryngology-Head and Neck Surgery, Sungkyunkwan University School of Medicine, Seoul, Korea.
7. Department Healthcare Center, Kyobo Life Insurance Co., Seoul, Korea.