[1] Wonkwang Univ, Sch Dent, Dept Periodontol, Iksan, South Korea
[2] Seoul Natl Univ, Bundang Hosp, Sect Dent, Dept Periodontol, Songnam 463707, South Korea
[3] Seoul Natl Univ, Bundang Hosp, Sect Dent, Dept Oral & Maxillofacial Surg, Songnam 463707, South Korea