[1] Texas A&M Univ, Sch Dent, Dept Periodont, Dallas, TX USA
[2] Texas A&M Coll Dent, Dept Periodont, 3302 Gaston Ave, Dallas, TX 75246 USA
[3] Univ Maryland, Sch Dent, Baltimore, MD USA
[4] Ohio State Univ, Coll Dent, Columbus, OH USA
[5] Univ Missouri, Sch Dent, Dept Periodont, Kansas City, MO USA