[1] Aalborg Univ Hosp, Dept Oral & Maxillofacial Surg, 18-22 Hobrovej, DK-9000 Aalborg, Denmark
[2] Aalborg Univ, Fac Med, Dept Clin Med, Aalborg, Denmark
[3] Aalborg Univ Hosp, Unit Clin Biostat, Aalborg, Denmark
[4] Aarhus Univ, Fac Hlth, Dept Dent & Oral Hlth, Sect Oral Radiol, Aarhus, Denmark