[1] Tohoku Univ, Dept Int & Community Oral Hlth, Grad Sch Dent, Sendai, Miyagi, Japan
[2] Tohoku Univ, Frontier Res Inst Interdisciplinary Sci, Sendai, Miyagi, Japan
[3] Tohoku Univ, Liaison Ctr Innovat Dent, Div Reg Community Dev, Grad Sch Dent, Sendai, Miyagi, Japan
[4] Chiba Univ, Ctr Prevent Med Sci, Dept Social Prevent Med Sci, Chiba, Japan
[5] Natl Ctr Geriatr & Gerontol, Ctr Gerontol & Social Sci, Dept Gerontol Evaluat, Obu, Japan
[6] Tokyo Med & Dent Univ, Grad Sch Med & Dent Sci, Dept Oral Hlth Promot, Tokyo, Japan