[1
]
Department of Periodontology, School of Dentistry, Periodontal-Implant Clinical Research
Institute, Kyung Hee University, Seoul, South Korea.
[2
]
Department of Periodontology, Dankook University College of Dentistry, Cheonan-si,
South Korea.
[3
]
Department of Periodontology, College of Dentistry, Seoul National University, Seoul,
South Korea.