1. Clinic of Reconstructive Dentistry Center of Dental Medicine University of Zurich Zurich Switzerland
2. Department of Prosthetic Dentistry Faculty of Medicine Medical Center – University of Freiburg Center for Dental Medicine University of Freiburg Freiburg Germany
3. Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders Humboldt-Universität zu Berlin and Berlin Institute of Health corporate member of Freie Universität Berlin Charité – Universitätsmedizin Berlin Berlin Germany
4. Faculty of Medicine Medical Center – University of Freiburg Center for Medical Biometry and Medical Informatics Institute for Medical Biometry and Statistics University of Freiburg Freiburg Germany