1. Dental Research Department, Postgraduate Dental Education Center, Örebro, Sweden;
2. School of Health and Medical Sciences, Örebro University, Örebro, Sweden;
3. Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden;
4. Department of Radiation Physics, Institute of Clinical Sciences at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden;
5. Department of Radiology, Skaraborg Hospital, Skövde, Sweden