1. Institute of Health Services Research in Dentistry University of Münster Münster Germany
2. Department of Epidemiology and Preventive Medicine University of Regensburg Regensburg Germany
3. Chair of Epidemiology University of Augsburg Germany
4. Institute for Medical Information Processing Biometry, and Epidemiology—IBE LMU Munich Munich Germany
5. Unit of Periodontology, Department of Restorative Dentistry, Periodontology, Endodontology, and Preventive and Pediatric Dentistry University Medicine Greifswald Greifswald Germany
6. Clinic for Periodontology and Conservative Dentistry University of Münster Münster Germany
7. Institute of Clinical Chemistry and Laboratory Medicine University Medicine Greifswald Greifswald Germany