[1] Helsinki Univ Hosp, Oral & Maxillofacial Dis, Head & Neck Ctr, HUS, POB 263,Kasarmikatu 11-13, FI-00029 Helsinki, Finland
[2] Univ Helsinki, HUS, POB 263,Kasarmikatu 11-13, FI-00029 Helsinki, Finland
[3] Karolinska Inst, Dept Dent Med, Huddinge, Sweden
[4] Univ Helsinki, Grp Adm, Helsinki, Finland
[5] Helsinki Univ Hosp, Helsinki, Finland
[6] Univ Eastern Finland, Dept Social & Hlth Management, Kuopio, Finland
[7] Helsinki Univ Hosp, Abdominal Ctr, Nephrol, Helsinki, Finland
[8] Folkhalsan Inst Genet, Folkhalsan Res Ctr, Helsinki, Finland