[1] Seoul Natl Univ, Bundang Hosp, Sect Dent, Dept Periodontol, Seoul 151, South Korea
[2] Yonsei Univ, Wonju Coll Med, Dept Internal Med, Seoul 120749, South Korea
[3] Seoul Natl Univ, Bundang Hosp, Seoul 151, South Korea
[4] Yonsei Plus Clin, Seoul, South Korea
[5] Wonkwang Univ, Sch Dent, Dept Periodontol, Iksan, South Korea
[6] Chung Ang Univ, Grad Sch, Dept Publ Hlth, Seoul, South Korea
[7] Seoul Natl Univ, Bundang Hosp, Med Res Collaborating Ctr, Seoul 151, South Korea
[8] Seoul Natl Univ, Sch Dent, Dept Oral Med & Oral Diagnosi, Seoul 151, South Korea