[1] Gangneung Wonju Natl Univ, Dept Oral Med & Diag, Coll Dent, Gangwon, South Korea
[2] Seoul Natl Univ, Sch Dent, Oromaxillofacial Dysfunct Res Ctr Elderly, Dept Oral Med & Oral Diag, Seoul, South Korea
[3] Seoul Natl Univ, Dent Res Inst, Seoul, South Korea