1. Private Practice Hürzeler/Zuhr Munich Germany
2. Department of Periodontology Center of Dentistry and Oral Medicine (Carolinum) Johann Wolfgang Goethe‐University Frankfurt/Main Germany
3. Private Practice DIE PRAXIS Berlin Germany
4. Center for Medical Biometry and Medical Informatics Institute for Medical Biometry and Statistics University Medical Center Freiburg Freiburg Germany
5. Department of Operative Dentistry and Periodontology University School of Dentistry Albert‐Ludwigs‐University Freiburg Germany
6. Private Practice Dr. Korte Soest Germany