1. Division of Oral and Maxillofacial Surgery, Department of Dentistry, College of Medicine, Hanyang University, Seoul, South Korea.
2. Division of Preventive Dentistry, Department of Dentistry, College of Medicine, Hanyang University, Seoul, South Korea.
3. Division of Conservative Dentistry, Department of Dentistry, College of Medicine, Hanyang University, Seoul, South Korea.
4. Division of Periodontology, Department of Dentistry, College of Medicine, Hanyang University, Seoul, South Korea.