1. Department of Clinical Dentistry, University of Oslo, Geitmyrsveien, Oslo, Norway
2. Department of Anaesthesiology, Lovisenberg Diakonale Hospital, Lovisenberggata 17, Oslo, Norway
3. The National Research Centre in Complementary and Alternative Medicine, University of Troms, Forskningsparken, Tromsø, Norway
4. Clinical Research Centre, University Hospital of North Norway, Tromsø, Norway