1. Department of Orthodontics, The Institute of Oral Health Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
2. Department of Oral Anatomy, Dental Research Institute and School of Dentistry, Seoul National University, Seoul, Korea.
3. Department of Dental Biomaterials Science, Dental Research Institute and School of Dentistry, Seoul National University, Seoul, Korea.
4. Department of Orthodontics, Dental Research Institute and School of Dentistry, Seoul National University, Seoul, Korea.
5. Private Practice, Seoul, Korea.
6. Section of Orthodontics, School of Dentistry, Center for Health Science, University of California, Los Angeles, USA.