Evaluation of the effects of guided bone regeneration and periosteum on newly formed bone in a distraction gap.

We determined the causes of bone resorption within a distraction gap and determined whether it could be prevented via guided bone regeneration during distraction. Another goal was to determine the effect of periosteum in bone healing in a distraction gap.Twelve sheep mandibles were bilaterally distracted. One side of the 6 sheep mandibles formed the control group; the other side was the study group, from which the periosteum was excised and distraction was performed. In the other 6 sheep, on the study side, guided bone regeneration was applied with distraction; on the other study side, guided bone regeneration was applied, and the periosteum was excised at the distraction. At the end of a 1-week latent period, all subjects were distracted 10 mm (1 mm/d), and we waited 3 months for consolidation. At the end of this period, all animals were killed, and radiologic evaluations of the newly formed bone within the distraction gap were conducted.The surface area of the regenerating bone in the membrane groups was significantly higher than in the groups without a membrane. However, no additional effect of the periosteum on the bone surface area was observed. No significant difference between the groups in densitometric values was observed.Concomitant use of guided bone regeneration with distraction osteogenesis may be the optimal way to generate a flat bone surface within a distraction gap.