1. Department of Periodontology, School of Dentistry, Kyung Hee University, Seoul 02447, Republic of Korea
2. Private Practice in Periodontics and Implant Dentistry, Seoul 02771, Republic of Korea
3. Department of Prosthdontics, Division of Dentistry, College of Medicine, Hanyang University, 222-1 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
4. Division of Periodontics, Section of Oral, Diagnostic and Rehabilitation Sciences, College of Dental Medicine, Columbia University, New York, NY 10027, USA
5. Department of Periodontology, Periodontal-Implant Clinical Research Institute, School of Dentistry, Kyunghee daero 23, Dongdaemoon-gu, Seoul 02447, Republic of Korea
6. Department of Periodontology, Division of Dentistry, College of Medicine, Hanyang University, 222-1 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea