1. The Clinic of Oral and Maxillofacial Radiology; Gothenburg Public Dental Service; Gothenburg Sweden
2. Department of Oral and Maxillofacial Radiology; Institute of Odontology at the Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
3. Department of Behavioral and Community Dentistry; Institute of Odontology at the Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden