1. EA 2496, U.F.R. of Odontology Paris Descartes University Montrouge France
2. Department of Periodontology U.F.R. of Odontology Rothschild Hospital, AP‐HP Paris Diderot University Paris, France
3. Department of Odontology Bretonneau Hospital, AP‐HP Hôpitaux Universitaires Paris Nord Val de Seine (Bretonneau) Paris France
4. Department of Periodontology Charles Foix Hospital, AP‐HP Hôpitaux Universitaires La Pitié Salpétrière – Charles Foix Paris France