1. Department of Oral Medicine Carolinas Medical Center 1000 Blythe Blvd P.O. Box 32861 Charlotte NC 28232‐2861 U.S.A
2. D.eb.RA. Mexico Foundation Otomí #211 casi esq. P. Elías Calles Colonia Azteca Guadalupe N.L. 67150 Monterrey Nuevo Leon Mexico
3. Department of Economics and Statistics Federico II University of Naples via Cinthia Monte Sant'Angelo 80126 Naples Italy
4. Department of Stomatology Cardarelli Hospital Via A. Cardarelli 9 80131 Naples Italy
5. Department of Basic Science Universidad de Monterrey Av. Ignacio Morones Prieto 4500 Pte. 66238 San Pedro Garza García Nuevo Leon México