4.

Morphology of calvarial regeneration and induction of bone formation in calvarial defects implanted with doses of the transforming growth factor-β₃ (hTGF-β₃) osteogenic device without (A) and with minced fragments of autogenous rectus abdominis muscle (E, F and G) harvested 90 days post-implantation. (A) Induction of bone in a calvarial defect implanted with 125 μg of the hTGF-β₃ osteogenic device showing bone formation predominantly on the pericranial aspect of the specimen with lack of bone formation at the endocranial dural aspect of the specimen (arrows). Arrows in B, C and D point to the inhibition of bone formation within the fibrogenic collagenous matrix facing the newly formed bone pericranially.(E, F and G). Addition to the hTGF-β₃ osteogenic device of autogenous minced fragments of rectus abdominis muscle induces partial restoration of the biological activity of 125 μg of the hTGF-β₃ osteogenic device with large islands of newly formed bone in specimens harvested on day 90 after implantation. Undecalcified sections cut at 5 μm stained free-floating with Goldner's trichrome. (A, E, F and G) original magnification ×1.8; (B, C and D) original magnification ×7.