Recombinant Human BMP-2 Enhances the Effects of Materials Used for Reconstruction of Large Cranial Defects
Presented at the Plastic Surgery Research Council Meeting 2005; the 10th International Congress on Cleft Palate and Related Craniofacial Anomalies 2005; and the 11th Biennial International Conference of the International Society of Craniofacial Surgery 2005.
Purpose
Cranial defect reconstruction presents 2 challenges: induction of new bone formation, and providing structural support during the healing process. This study compares quantity and quality of new bone formation based on various materials and support frameworks.
Materials and Methods
Eighteen dogs underwent surgical removal of a significant portion of their cranial vault. Demineralized bone matrix was used to fill the defect in all animals. In 9 dogs, recombinant human bone morphogenetic protein-2 (rhBMP-2) was added, while the other 9 served as the non-rhBMP-2 group. In each group, 3 animals were fixed with cobalt chrome plates, 3 with adding platelet-rich plasma, and 3 fixed with a Lactosorb (Walter Lorenz Surgical, Inc, Jacksonville, FL) resorbable mesh. Necropsy was done at 12 weeks postoperative. Histomorphometry, density, and mechanical properties of the regenerate were analyzed.
Results
The non-rhBMP-2 groups showed minimal substitution of demineralized bone matrix with new bone, while only sporadic remnants of demineralized bone matrix were present in the rhBMP-2 groups. The defect showed more new bone formation (P < .001) and density (P < .001) in the rhBMP-2 groups by Kruskal-Wallis test. The area of new bone was not significantly different among the rhBMP-2 subgroups. The resorbable mesh struts showed no sign of bone invasion or substitution. In the non-rhBMP-2 resorbable mesh group, demineralized bone matrix almost totally disintegrated without replacement by new bone.
Conclusions
The addition of rhBMP-2 to demineralized bone matrix accelerated new bone formation in large cranial defects, regardless of the supporting framework or the addition of platelet-rich plasma. The use of a resorbable mesh in such defects is advisable only if rhBMP-2 is added.
⁎Assistant Professor, Department of Oral Biology and Maxillofacial Pathology, and the Department of Oral and Maxillofacial Surgery, School of Dentistry, Medical School of Georgia, Augusta, GA.
†Registrar, Department of Plastic, Reconstructive, and Aesthetic Surgery, KK Women’s and Children’s Hospital, Singapore.
‡Director, International Craniofacial Institute, and Cleft Lip and Palate Treatment Center, Medical City, Dallas, TX; and Adjunct Assistant Professor, Department of Biomedical Sciences, Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, TX.
§Chairman, World Craniofacial Foundation, Dallas, TX; and Adjunct Professor, Department of Orthodontics, Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, TX.
∥Assistant Professor, Department of Anatomy, Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, GA.
¶Medical Director, International Craniofacial Institute and Cleft Lip and Palate Treatment Center, Medical City, Dallas, TX.
⁎⁎Professor Emeritus of Research Orthopaedics, University of Southern California, Los Angeles, CA; and President and Chief Executive Officer, Pacific Coast Tissue Bank, Los Angeles, CA.
††Associate Professor, Department of Biomedical Sciences, and Director of Technology Development, Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, TX.
Address correspondence and reprint requests to Dr Genecov: International Craniofacial Institute, Cleft Lip and Palate Treatment Center, 7777 Forest Lane, Suite C717, Dallas, TX 75230
ABSTRACT