1. Department of Periodontology & Oral Implantology; Dental School; Faculty of Medicine and Health Sciences; University of Ghent; Ghent Belgium
2. Department of Prosthodontics; Faculty of Odontology; Malmö University; Malmö Sweden
3. Department of Oral and Maxillofacial Prosthodontics and Oral Implantology; Institute of Health Biosciences; The University of Tokushima Graduate School; Tokushima Japan
4. Center for Medical Genetics; Faculty of Medicine and Health Sciences; Ghent University Hospital; Ghent Belgium
5. Department of Restorative and Prosthetic Dentistry; The Ohio State University College of Dentistry; Columbus OH USA