The purpose of this study was to compare the consolidation periods in ADO and to evaluate its effects on bone formation and implant success in severely resorbed edentulous mandibles.

Patients and methods: Severely resorbed eighteen mandibles were augmented with vertical ADO and were submitted to the same distraction protocol except for variations in consolidation time. After a one-week latent period, the distractors were activated for 0.5 mm/day, for 20 days. After a consolidation period of five weeks for Group 1 ( n : 9) and 12 weeks for Group 2 ( n : 9), two implants per patient were placed to support the dentures. Bone specimen was harvested from the implant space with trephine bur during the drilling for histological examination. Hematoxylin-eosin stain was used for histological examination, and bone labeling was observed with fluorescence microscope. Ossification and bone healing were evaluated using ortopantomographic radiographs from the beginning of distraction up to one year fallow up.

Results: In all cases distraction procedure was applied successfully and enough bone augmentation was achieved. Tubular bone formation was observed in both groups. These bone formation were parallel oriented to the distraction vector. In the comparison of consolidation times, fibrosis was higher in group 1, and tubular bone formation was higher in group 2. At the end of consolidation period distraction gaps were mostly still radiolucent in group 1, while almost radio-opaque in group 2, but still some radiolucent areas were observed at the center.

Conclusion: Bone formation in five weeks consolidation following ADO procedure looks radiologically and histologically sufficient for implant placement.

Conflict of interest: None declared.