1Department of Periodontology, College of Dentistry, Seoul National University, Korea.
2Department of Cardiology, College of Medicine, Seoul National University, Korea.
3Department of Dentistry, College of Medicine, Sungkyunkwan University, Korea.
4Department of Periodontology, College of Dentistry, Chonnam National University, Korea.
Corresponding author: In-Cbul Rbyu, Department of Periexlontology, College of Dentistry, Seoul National University, 28, Yangon-Dong, Cbongno-Gll, 110-749, Seoul, Korea.