48 year old female presents with a history of car accident 16 years prior and loss of her maxillary anterior teeth. During the maxillary single-stage ridge split, buccal cortical plate is separated and dislocated laterally. It is still connected to the buccal muco-periosteal flap and gets vascularity from it. The particulate graft that is placed into the split in the inlay fashion also needs blood supply to heal (integrate). It gets blood supply from 3 sources:
1. Periosteal buccal (luxated complex)
2. Periosteal palatal (intact complex)
3. Osteal- from the underlying native alveolar ridge.

source vascularity is the best that you can obtain for the healing of the inlay (interpositional) graft. That is one of the reasons why this procedure (ridge-split or sandwich osteotomy) is so successful. Because of an amazing inherent vascularization of the particulate graft sandwiched in-between natural vascularized bone on both sides with this technique.

Block graft is very different. Let's discuss it. How many sources of blood supply, do you think, is available for the autogenous onlay block bone graft after transplantation at the recipient site?