1. Department of Prosthodontics, Dental Clinic Center, Chungbuk National University Hospital, Cheongju, Korea.
2. Division of Pulmonary Medicine and Allergy, Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea.
3. Department of Mathematics, College of Natural Sciences, Hanyang University, Seoul, Korea.
4. Division of Pulmonary Medicine, Department of Internal Medicine, Chungbuk National University College of Medicine and Chungbuk National University Hospital, Cheongju, Korea.
5. Division of Endocrinology and Metabolism, Department of Internal Medicine, Chungbuk National University College of Medicine and Chungbuk National University Hospital, Cheongju, Korea.