1. Department of Oral Pathology, Radiology and Medicine, University of Iowa, Iowa City, Iowa, and Dows Research Institute, College of Dentistry, University of Iowa.
2. Department of Oral and Maxillofacial Surgery, Faculty of Dental Sciences, University of Lagos.
3. Dundee Dental School and Hospital, University of Dundee, United Kingdom.
4. Department of Oral and Maxillofacial Surgery, University of Maiduguri Teaching Hospital.
5. Department of Plastic Surgery, National Orthopedic Hospital, Enugu.
6. Department of Oral and Maxillofacial Surgery, Aminu Kano University Teaching Hospital.
7. Department of Oral and Maxillofacial Surgery, Federal Medical Center, Gombe.
8. Department of Oral and Maxillofacial Surgery, Federal Medical Center Nguru.
9. Division of Ear, Nose and Throat, Department of Surgery;
10. Department of Pediatrics, University of Iowa, Iowa City, Iowa.
11. Department of Community Health and Primary Care, University of Lagos.