1. Department of Otorhinolaryngology-Head & Neck Surgery and Cancer Research Institute; Seoul National University, College of Medicine; Seoul Korea
2. Department of Statistics; Hallym University; Chuncheon Korea
3. Department of Otorhinolaryngology-Head & Neck Surgery; Thyroid/Head & Neck Cancer Center of the Dongnam Institute of Radiological & Medical Sciences (DIRAMS); Busan Korea
4. Department of Otorhinolaryngology-Head & Neck Surgery; Hallym University Sacred Heart Hospital; Anyang Korea