The use of intraorally harvested autogenous block grafts for vertical alveolar ridge augmentation: a human study

This study presents a clinical, radiographic, laboratory, and histologic/histomorphometric analysis of the use of mandibular block autografts for vertical alveolar ridge augmentation. Twelve patients were included in the study. The autogenous block autografts were fixated at the recipient sites with screws, and a mixture of autogenous bone marrow and inorganic bovine mineral (Bio-Oss) was used at the periphery. At re-entry surgery, all the grafts appeared well incorporated at the recipient sites. Radiographic measurements revealed an average of 5.75 +/- 1.29 mm vertical ridge augmentation at 1 month after surgery and 4.75 +/- 1.29 mm at 4 to 6 months after surgery. This indicated 17.4% resorption. Laboratory volumetric measurements revealed an average of 0.84 +/- 0.34 mL of alveolar ridge augmentation 1 month after surgery and 0.71 +/- 0.28 mL at 6 months postoperatively. The resorption rate according to the laboratory volumetric measurements was 15.5%. Linear laboratory measurements revealed 5.92 +/- 1.38 mm of vertical ridge augmentation 1 month postoperatively and 4.08 +/- 1.01 mm at 4 to 6 months after surgery. Histologic evaluation of the block autografts indicated signs of active remodeling activity in 10 of the 12 specimens. In one case the block graft became exposed and infected, and in another case the block autograft became dislodged during implant placement surgery. Histomorphometric analysis of the peripheral particulate bone indicated bone present at 33.99% +/- 8.82% of the graft surface, while 42.43% +/- 11.06% of the area was occupied by fibrous tissue and 23.89% +/- 9.12% was made up of residual Bio-Oss particles. Residual Bio-Oss particles were in tight contact with newly formed bone along 58.57% +/- 15.22% of their perimeter.