[1] Univ Bergen, Dept Clin Dent, Pediat Dent, Fac Med, Arstadveien 19, N-5009 Bergen, Norway
[2] Mid Norway TkMidt, Ctr Oral Hlth Serv & Res, Trondheim, Norway
[3] Haukeland Hosp, Dept Oral & Maxillofacial Surg, Bergen, Norway
[4] Karolinska Inst, Dept Dent Med, Sect Oral Diagnost & Surg, Huddinge, Sweden
[5] Norwegian Univ Sci & Technol, Fac Med & Hlth Sci, Dept Publ Hlth & Nursing, Trondheim, Norway
[6] Publ Dent Hlth Serv Competence Ctr Northern Norwa, Tromso, Norway
[7] UiT Arctic Univ Norway, Fac Hlth Sci, Dept Clin Med, Tromso, Norway
[8] Univ Hosp North, Div Oral & Maxillofacial Surg, Dept Otorhinolaryngol, Tromso, Norway
[9] NTNU Norwegian Univ Sci & Technol, Dept Clin & Mol Med, Trondheim, Norway
[10] St Olavs Hosp, Dept Pediat, Trondheim, Norway
[11] Oral Hlth Ctr Expertise Western Norway Hordaland, Trondheim, Norway