1. Department of Clinical Dentistry-Center for Clinical Dental Research, Faculty of Medicine and Dentistry, University of Bergen - Norway
2. Department of Fiber and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm - Sweden
3. Department of Clinical Dentistry-Section of Oral and Maxillofacial Surgery, Faculty of Medicine and Dentistry, University of Bergen - Norway
4. Department of Maxillofacial Plastic Surgery, First Affiliated Hospital of Medical College, Xi'an Jiaotong University - China