1. a Associate Professor, Department of Orthodontics, College of Dentistry, Kangnung National University, Kangnung, Kangwondo, Republic of Korea
2. b Graduate student (PhD), Department of Orthodontics, College of Dentistry, Kangnung National University, Kangnung, Kangwondo, Republic of Korea
3. c Full-time lecturer, Department of Orthodontics, College of Dentistry, Kangnung National University, Kangnung, Kangwondo, Republic of Korea
4. d Associate Professor, Department of Orthodontics, School of Dentistry, Dental Research Institute, Seoul National University, Seoul, Republic of Korea