1. Department of Periodontics, Penn Dental Medicine; University of Pennsylvania; Philadelphia PA USA
2. Department of Applied Oral Sciences; Forsyth Institute; Cambridge MA USA
3. Department of Dental Ecology; School of Dentistry; University of North Carolina at Chapel Hill; Chapel Hill NC USA
4. Department of Biostatistics; Gillings School of Global Public Health; University of North Carolina at Chapel Hill; Chapel Hill NC USA
5. Department of Oral Biology; School of Dental Medicine; State University of New York at Buffalo; Buffalo NY USA
6. Department of Periodontics and Oral Medicine; Michigan Center for Oral Health Research; University of Michigan School of Dentistry; Ann Arbor MI USA
7. New York University College of Dentistry; Bluestone Center for Clinical Research; New York NY USA
8. Section of Periodontics; Department of Applied Dental Medicine; Southern Illinois University School of Dental Medicine; Alton IL USA
9. Rho Inc., Contract Research Organization; Chapel Hill NC USA