[1] Columbia Univ, Div Periodont, Sect Oral & Diagnost Sci, Coll Dent Med, New York, NY 10032 USA
[2] Columbia Univ, Coll Dent Med, Div Community Hlth, New York, NY 10032 USA
[3] Columbia Univ, Dept Biostat, Mailman Sch Publ Hlth, New York, NY 10032 USA