Gian Paolo Bombeccari1,2, Aldo Bruno Giannì1,2, Francesco Spadari1,2. 1. Maxillo-Facial and Dental Unit, Fondazione Ca' Granda IRCCS Ospedale Maggiore Policlinico, Milan, Italy. 2. Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy.