1 Professor Emeritus and Former Chair, Department of Preventive Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN.
2 Professor Emeritus, Division of Periodontology, Department of Developmental and Surgical Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN.
3 Professor, Division of Periodontology, Department of Developmental and Surgical Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN.