1. Division of Periodontology, Department of Dentistry, Hanyang University College of Medicine, Seoul, Korea.
2. Division of Periodontology, Department of Dentistry, Hanyang University Medical Center, Seoul, Korea.
3. Division of Orthodontics, Department of Dentistry, Hanyang University Medical Center, Seoul, Korea.
4. Division of Oral & Maxillofacial Surgery, Department of Dentistry, Hanyang University College of Medicine, Seoul, Korea.