1. School of Dental Medicine, Department of Oral Biology, University of Pittsburgh, Bridgeside Point Suite 500, 100 Technology Drive, Pittsburgh, PA 15219, USA
2. Center for Oral Health Research in Appalachia (COHRA), University of Pittsburgh, Pittsburgh, PA 15219, USA
3. School of Dentistry, Department of Dental Practice & Rural Health, Eberly College of Arts and Sciences, Department of Psychology, West Virginia University, 53 Campus Drive, P.O. Box 6040, Morgantown, WV 26506, USA
4. School of Public Health, Department of Epidemiology, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109, USA
5. School of Dental Medicine, Department of Dental Public Health, University of Pittsburgh, 3501 Terrace Street, Pittsburgh, PA 15213, USA
6. Graduate School of Public Health, Department of Human Genetics, University of Pittsburgh, 130 De Soto Street, Pittsburgh, PA 15261, USA
7. Department of Periodontics, West Virginia University, Room G110-B HSC, N. Medical Center Drive, Morgantown, WV 26506, USA
8. Department of Obstetrics, Gynecology and Reproductive Sciences, Magee-Womens Hospital, University of Pittsburgh Medical Center, 300 Halket Street, Pittsburgh, PA 15213, USA
9. University Center for Social and Urban Research, 3343 Fifth Avenue, Pittsburgh, PA 15213, USA