1. Department of Epidemiology and Preventive Medicine University of Regensburg Regensburg Germany
2. Chair of Epidemiology University of Augsburg, University Hospital Augsburg Augsburg Germany
3. Department of Dermatology University of Michigan Medical School Ann Arbor Michigan USA
4. Department of Computational Medicine and Bioinformatics University of Michigan Ann Arbor Michigan USA
5. Department of Biostatistics, Center for Statistical Genetics University of Michigan Ann Arbor Michigan USA
6. Ann Arbor Veterans Affairs Hospital Ann Arbor Michigan USA
7. Clinic for Periodontology and Conservative Dentistry University of Münster Münster Germany
8. Department of Restorative Dentistry, Periodontology, Endodontology, and Preventive and Pediatric Dentistry University Medicine Greifswald Greifswald Germany
9. Institute of Health Services Research in Dentistry University of Münster Münster Germany