1. Department of Periodontology School of Dental Medicine University of Bern Bern Switzerland
2. Department of Oral and Maxillofacial Surgery Copenhagen University Hospital Copenhagen Denmark
3. Research Area Oral Rehabilitation, Section for Oral Health, Society and Technology Institute of Odontology, Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
4. Research Area Oral Surgery, Section for Oral Biology and Immunopathology Institute of Odontology, Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark