1. University of Plymouth; Peninsula Dental School; The John Bull Building, Tamar Science Park, Plymouth UK PL6 8BU
2. University of Bern; Department of Orthodontics and Dentofacial Orthopedics; Freiburgstr. 7 Bern Switzerland CH-3010
3. Queen Mary University of London; Barts and The London School of Medicine and Dentistry; Institute of Dentistry New Road London UK E1 1BB
4. The Cochrane Collaboration; UKCC (Bahrain Branch); Box 25438 Awali Bahrain
5. University of Texas Health Science Center at San Antonio; Department of Oral and Maxillofacial Surgery; 7703 Floyd Curl Dr, MC 7908 San Antonio USA TX 78229-3900
6. Peninsula Dental School, University of Plymouth; The John Bull Building Tamar Science Park Plymouth UK PL6 8BU