1. Oral and Maxillofacial Surgery, University Medical Center of the Johannes Gutenberg-University Mainz, Germany.
2. Institute of Dental Implants and Periodontics, Gurnee, Ill.
3. Private practice, Puerto de Los Leones, Madrid, Spain.
4. Freiberger Dental Practice, London, UK.
5. Clínica Ortiz-Vigón S.L., Vizcaya, Spain.
6. Private practice, Paris, France.
7. Faculty of Medicine of University of Coimbra (FMUC), Coimbra, Portugal.