Guided tissue regeneration enhances bone formation in a rat model of failed osteogenesis.
BACKGROUND
Guided tissue regeneration is a technique that uses barrier materials to enhance tissue regeneration. Although previously demonstrated to be an effective way of enhancing craniofacial osteogenesis in several animal models, the ability of guided tissue regeneration to augment bone formation in the context of distraction osteogenesis is unknown. In the current study, the authors applied the principle of guided tissue regeneration to their rat mandibular distraction osteogenesis model in an attempt to enhance bone regeneration.


METHODS
Twelve (n = 6 per group) adult Sprague-Dawley rats underwent routine gradual distraction (5 days' latency, 4-mm distraction over 8 days, 4 to 6 weeks of consolidation) and acute distraction (immediate lengthening to 4 mm, 6 to 8 weeks of consolidation). An additional 10 animals underwent acute distraction followed by application of bioabsorbable Gore Resolut XT membranes (acute distraction plus guided tissue regeneration). Membranes were completely wrapped around the distraction gap. Animals were killed 6 and 8 weeks postoperatively and mandibles analyzed radiographically and histologically.


RESULTS
Quantitative histomorphometric analyses were performed to compare relative bone formation between all three groups. Gradual distraction mandibles achieved bony union by 6 weeks with 86 percent bone formation, which increased to 98 percent by 8 weeks. Acute distraction mandibles healed with a fibrous nonunion and only 37 percent bone formation by 8 weeks. In contrast, acute distraction plus guided tissue regeneration-treated mandibles formed significantly more bone than acute distraction mandibles by 6 weeks (57 percent) and achieved bony bridging by 8 weeks, with 88 percent new bone formation.


CONCLUSIONS
The authors' data demonstrate that guided tissue regeneration can significantly enhance bone formation in a fibrous nonunion model of mandibular distraction osteogenesis.
Fang
Tony D
TD
Children's Surgical Research Program, Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA.
Nacamuli
Randall P
RP
Song
Han Joon M
HJ
Fong
Kenton D
KD
Shi
Yun-Ying
YY
Longaker
Michael T
MT
D000818:Animals; D001861:Bone Regeneration; D048091:Guided Tissue Regeneration; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery; D019857:Osteogenesis, Distraction; D019736:Prostheses and Implants; D011859:Radiography; D051381:Rats; D017207:Rats, Sprague-Dawley