1. Section for Epidemiology and Social Medicine; Institute of Medicine; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
2. Primary Health Care Unit; Institute of Medicine; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
3. Research & Development Unit in Southern Alvsborg County; Boras Sweden
4. Department of Oral and Maxillofacial Radiology; Institute of Odontology at the Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
5. Department of Behavioral and Community Dentistry; Institute of Odontology at the Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden