1. Department of Maxillofacial Surgery Oslo University Hospital Ullevål Oslo Norway
2. Department of Anaesthesiology Division of Emergencies and Critical Care Oslo University Hospital Ullevål Oslo Norway
3. Institute of Clinical Medicine Faculty of Medicine University of Oslo Oslo Norway
4. Department of Oral Biology Faculty of Dentistry University of Oslo Oslo Norway
5. Department of Neurosurgery Oslo University Hospital Ullevål Oslo Norway