[1] Univ Minnesota, Sch Dent, Dept Primary Dent Care, Div Dent Therapy, Minneapolis, MN 55455 USA
[2] Univ Minnesota, Sch Dent, Dept Diagnost & Biol Sci, Div Oral Med Diag & Radiol, Minneapolis, MN USA
[3] Univ Minnesota, Sch Publ Hlth, Div Epidemiol & Community Hlth, Minneapolis, MN USA
[4] Univ Minnesota, Sch Dent, Dept Primary Dent Care, Div Dent Hyg, Minneapolis, MN USA