Augmentation of severe bony defects with intraoral bone grafts: biological approach and long-term results

      Autogenous bone graft is still the gold standard for the reconstruction of severe atrophy of the maxilla or the mandible. Two and three-dimensional bony defects need for the reconstruction special surgical procedures with autogenous bone grafts to assure at long-term an acceptable functional and esthetical result. Biomaterials have here their limitation and are for such reconstruction until today not an alternative due to their poor regeneration potential.
      Autogenous bone graft harvested from intraoral sites, especially the retromolar area of the mandible, and used following the split bone block (SBB) technique is offering many possibilities for intra operative facilities and stable long-term results. Splitting the thick cortical block to 2 or 3 thin blocks is augmenting the number of blocks allowing the reconstruction of larger atrophic crest and giving a better adaptation to the recipient site with individual determination of the width and the volume of the grafted area. Filling the space and gaps between the thin block and the remaining crest with particulate bone chips is reducing the time needed for revascularisation of the graft improving its vitality compared to the original thick block.
      Many studies demonstrate that the reconstruction of horizontal and vertical atrophied crest with thin mandibular blocks in combination with particulate bone grafts, without any biomaterial or membrane, offer over years, through the high vitality of the grafted and regenerated bone, a stable periimplant bone level.
      15 years results on more of 1300 grafting procedure for horizontal and vertical bone augmentation present a low complication rate and showed that changes of the volume of the grafted bone occurred up to one year after the grafting procedures and stays stable for more than 15 years. Limited bone resorptions were observed, especially when the bone block was grafted outside the bone contours, but without negative influence on the definitive treatment. Implants inserted in this grafted bone presented similar osseointegration as implants placed in non-grafted bone.