1. Dong-A University College of Medicin, Busan, Korea.
2. Department of Otolaryngology-Head and Neck Surgery, Dong-A University College of Medicine, Busan, Korea.
3. Department of Preventive Medicine, Dong-A University College of Medicine, Busan, Korea.
4. Department of Endocrinology, Dong-A University College of Medicine, Busan, Korea.