Stereologic Analysis of Bone Produced by Distraction Osteogenesis or Autogenous Bone Grafting in Mandible

To our knowledge, in the literature, any other investigation that numerically compared osteoblasts retrieved from transport distraction osteogenesis and bone grafting procedures using stereological methods is not reported. The purpose of this study was to compare the total number of osteoblast cells at 3 months in bone produced by distraction osteogenesis and that in autogenous bone graft. A total of 19 growing sheep (male aged 7 or 8 mo; weighing between 21 and 28 kg) were used in this study. Mandibular discontinuity defects created in mandibles of sheep were reconstructed by transport distraction osteogenesis and iliac crest bone graft and allowed to heal for 3 months. The animals were then killed, and the jaws were resected and prepared to be decalcified. Stereological and histologic examinations were performed. Intramembranous ossification and osteoid and trabecular formations were observed in both groups. In the distraction group, the mean T standard deviation (SD) numerical density of the osteoblasts was found to be higher (0.0004866 +/- [0.000044]) when compared with those of both the graft (0.0003458 +/- [0.000030]) and control groups (0.0002714 +/- [0.000022]). Statistically significant differences were found among the groups (P < 0.05). Stereologic evaluation of bone in the sheep model demonstrated significantly greater osteoblast density in bone formed through transport distraction osteogenesis when compared with bone grafting and the control. Therefore, further studies should be conducted to evaluate the differences in both osteoblastic and osteoclastic cellular activities at different time points in distraction osteogenesis and autogenous bone grafting to assess the healing process of bone for clinical applications.