Purpose: This study compared the histologic parameters and outcomes of two types of grafts in large vertical maxillary defects: a composite graft of recombinant human bone morphogenetic protein-2/acellular collagen sponge (rhBMP-2/ACS), crushed cancellous freeze-dried allogeneic bone (CCFDAB), and platelet-rich plasma (PRP); and size-matched 100% autogenous grafts. Materials and Methods: Twenty patients each were treated with a composite graft, which contained 1.05 mg rhBMP-2/ACS per two-tooth segment together with CCFDAB and PRP, or a 100% autogenous graft prior to implant placement. Grafting material was contained within a titanium mesh crib. Results: Two grafts in each group were lost as a result of early mesh exposure and infection. Three grafts in each group developed a late exposure of the mesh that did not affect bone regeneration. The remaining 18 autogenous grafts all regenerated sufficient bone for implant restoration (100%), and 17 of 18 (97.4%) of the composite grafts regenerated sufficient bone for implant restoration. The autogenous grafts included 54% ± 10% of new viable bone but also included residual nonviable graft particles. The composite grafts contained 59% ± 12% viable new bone and no remaining nonviable bone particles. The composite grafting technique resulted in less blood loss and shorter surgical time but greater and longer-lasting edema. The costs of both grafts were nearly equal. Conclusion: A composite graft of rhBMP-2/ACS-CCFDAB-PRP regenerates bone in large vertical ridge augmentations as predictably as 100% autogenous graft with less morbidity, equal cost, and more viable new bone formation without residual nonviable bone particles, but with more edema. This composite graft represents an in situ tissue engineering concept that is able to achieve results equivalent to autogenous grafts in large vertical ridge augmentations without donor bone harvesting.