[1] Univ Bern, Sch Dent Med, Dept Restorat Prevent & Pediat Dent, Freiburgstr 7, CH-3010 Bern, Switzerland
[2] Univ Sassari, Sch Dent, Dept Surg Microsurg & Med Sci, Piazza Univ 21, I-07100 Sassari, Italy
[3] Sechenov First Moscow State Med Univ, Sch Dent, Dept Pediat Prevent Dent & Orthodont, Moscow 119435, Russia
[4] Aarhus Univ, Inst Odontol & Oral Hlth, Sect Orofacial Pain & Jaw Funct, DK-8000 Aarhus C, Denmark
[5] Johannes Gutenberg Univ Mainz, Univ Med Ctr, Periodontol & Operat Dent, Augustuspl 2, D-55131 Mainz, Germany