The bony residual ridge in man.

The bone which fills in the socket after tooth extractions was investigated in 120 dry skull specimens and 100 radiographs in which one or more teeth had been missing for at least three months. The bony content of the socket was of the trabecular type. This trabecular bone was well differentiated from the adjacent cortical bony plates. In buccolingual sections, the residual crest was formed by dense trabecular bone, clearly differentiated from the cortical plates as well as from the less dense trabecular bone that was deeper within the former sockets. From the occlusal aspect, the crest of the edentulous surface had shifted lingually when compared to the original position of the teeth before extractions. From the lateral aspect, the residual ridge formed a concavity or went straight between the alveolar crests of the adjacent remaining teeth. When several teeth were missing, the concavity was more pronounced than when a single tooth was missing.