1. Department of Otorhinolaryngology–Head and Neck Surgery, Korea University College of Medicine, Seoul
2. Department of Otorhinolaryngology–Head and Neck Surgery, Sanggye Paik Hospital, College of Medicine, Inje University, Gimhae
3. Department of Neurosurgery, Korea University College of Medicine, Gyeonggi-do
4. Department of Otorhinolaryngology–Head and Neck Surgery, Chung-Ang University College of Medicine, Seoul, Republic of Korea