1. School of Dentistry, Chonnam National University, Gwangju, Korea.
2. Northwestern University, USA.
3. Department of Prosthodontics, School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju, Korea.
4. Department of Orthodontics, School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju, Korea.