1. Dept. of Health Policy & Health Services Research and
2. Dept. of Periodontology and Oral Biology, Boston University Goldman School of Dental Medicine, 715 Albany St., 560, 3rd floor, Boston, MA 02118, USA;
3. Dept. of Epidemiology, Harvard School of Public Health;
4. New England Research Institutes;
5. University of Puerto Rico, Division of Dental Public Health, School of Dentistry, Medical Science Campus; and