1. Department of Periodontology; Faculty of Odontology; University of Malmö; Malmö Sweden
2. Division of Oral Surgery; University Clinic of Dentistry; Medical University of Vienna; Vienna Austria
3. Department of Oral Rehabilitation; School of Dentistry; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
4. Department of Oral and Maxillofacial Surgery; Copenhagen University Hospital (Rigshospitalet); Copenhagen Denmark
5. Division of Conservative Dentistry and Periodontology; University Clinic of Dentistry; Medical University of Vienna; Vienna Austria