The use of ramus autogenous block grafts for vertical alveolar ridge augmentation and implant placement: a pilot study
Proussaefs, P.; Lozada, J.; Kleinman, A.; Rohrer, M.D.
International Journal of Oral and Maxillofacial Implants 17(2): 238-248
2002
ISSN/ISBN: 0882-2786 PMID: 11958407 Document Number: 541414
This study presents a clinical, radiographic, laboratory, and histologic/histomorphometric analysis of the use of mandibular ramus block autografts for vertical alveolar ridge augmentation and implant placement. Autogenous block autografts were fixed at the recipient site with fixation screws while a mixture of autogenous bone marrow and inorganic bovine material (Bio-Oss) was used at the periphery. All grafts appeared well incorporated at the recipient site during reentry surgery. Radiographic measurements revealed an average of 6.12 mm vertical ridge augmentation 1 month after surgery and 5.12 mm 4 to 6 months after surgery. Laboratory volumetric measurements revealed an average of 0.91 mL alveolar ridge augmentation 1 month after surgery and 0.75 mL 6 months postoperatively. Linear laboratory measurements revealed 6.12 mm of vertical ridge augmentation 1 month postoperatively and 4.37 mm 4 to 6 months after surgery. Histologic evaluation indicated signs of active remodeling in all the specimens. Histomorphometric analysis of the peripheral particulate bone indicated bone present at 34.33% of the grafted area, while 42.17% of the area was occupied by fibrous tissue and 23.50% by residual Bio-Oss particles. The results demonstrated the potential of mandibular block autografts harvested from the ascending ramus to maintain their vitality. Volumetric resorption rate of 17.58% and radiographic resorption rate of 16.34% were in accordance with previously published literature. Early exposure appeared to compromise the results, while late exposures did not affect the vitality of the block autografts. Mandibular block autografts can maintain their vitality when used for vertical alveolar ridge augmentation. Inorganic bovine mineral (Bio-Oss) can be used at the periphery of the block graft when mixed with autogenous bone marrow.