HUMAN RECOMBINANT TRANSFORMING GROWTH-FACTOR-BETA-1 IN HEALING OF CALVARIAL BONE DEFECTS

Bone healing plays an important role in orthognathic and craniofacial surgery. Bone tissue repair and regeneration are regulated by an array of growth and morphogenetic factors. Osteogenesis proceeds through a cascade of molecular and cellular events sequentially coordinated by m embers of both the bone morphogenetic protein and transforming growth factor-beta (TGF-beta) families. The efficacy of a single application of 2, 5, or 10 mu g of recombinant human (rh) TGF-beta 1 to promote bo ne regeneration in 5-mm experimental calvarial defects of adult male r ats was assessed histologically and histomorphometrically. The histomo rphometric results of the experimental site were compared with those o f the contralateral control side. Dose-group comparisons were also per formed. None of the control and experimental bone defects demonstrated complete bone closure. Limited bone regeneration was found close to t he margins of the defects. A statistically significant difference in v olume fraction composition (bone, osteoid, and soft tissue) was found between the 5- and 10-mu g rhTGF-beta 1-implanted and control defects. No difference was found in the 2-mu g rhTGF-beta 1-implanted group. T he percentage of bone closure was statistically significantly higher i n the 5-mu g rhTGF-beta 1-implanted group than in the control group. T he present findings indicate that a single application of different do ses of rhTGF-beta 1 does not promote clinically relevant osteogenesis in membranous calvarial bone defects in adult rats.