1. Department of Conservative Dentistry; School of Dentistry; Prince of Songkla University; Hat Yai Songkla Thailand
2. Department of Dental Ecology; School of Dentistry; University of North Carolina; Chapel Hill NC USA
3. Department of Epidemiology; Gillings School of Global Public Health; University of North Carolina; Chapel Hill NC USA
4. Department of Biostatistics; Gillings School of Global Public Health; University of North Carolina; Chapel Hill NC USA
5. Division of Geriatrics and Gerontology; Department of Medicine; University of Mississippi Medical Center; Jackson MS USA
6. Cerebrovascular Center; School of Medicine; The Johns Hopkins Hospital; Baltimore MD USA
7. Division of Epidemiology and Community Health; School of Public Health; University of Minnesota; Minneapolis MN USA