1. Department of Preventive and Community Dentistry, Indiana University School of Dentistry, 415 Lansing Street, OH-144, Indianapolis, IN 46202, USA
2. Research Center, University of Puerto Rico School of Dentistry, Medical Sciences Campus, P.O. Box 365057, San Juan, PR 00936
3. Department of Biostatistics, Indiana University School of Medicine, 410 W. Tenth Street, Suite 3000, Indianapolis, IN 46202
4. School of Professional Development of the Brazilian Association of Dentistry, Rua Dias da Rocha Filho, 625 Alto da Rua XV, Curitiba - PR, Brasil 80040-050