1. Graduate Student, Dental Research Institute and Department of Oral Microbiology and Immunology, School of Dentistry, Seoul National University, Seoul, Korea.
2. Clinical Lecturer, Department of Orthodontics, Seoul National University Gwanak Dental Hospital, Seoul, Korea.
3. Research Assistant, Dental Research Institute, Seoul National University, Seoul, Korea.
4. Professor, Dental Research Institute and Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, Korea.