1. Associate Professor, West Virginia University, Department of Dental Practice and Rural Health, School of Dentistry, 104a Health Sciences Addition, PO Box 9415, Morgantown, WV 26506, USA
2. West Virginia University, Department of Epidemiology, School of Public Health, Robert C Byrd Health Sciences Center North, Room G104C, Morgantown, WV 26506, USA
3. Associate Professor, West Virginia University, Department of Dental Hygiene, School of Dentistry, Robert C Byrd Health Sciences Center North, Room 1192A, Morgantown, WV 26506, USA
4. West Virginia University, Department of Dental Research, School of Dentistry, 106a Health Sciences Addition, PO Box 9448, Morgantown, WV 26506, USA