Bundle bone (or alveolar bone proper) constitutes, at least in part, the hard tissue lining of the socket and serves as the lateral anchorage for the principal fibers of the periodontal ligament (for review, see Schroeder 1986). The bundle bone is continuous with the lamellar bone and the distinct orientated trabeculae in the cancellous bone of the alveolar process. Bundle bone with typical Sharpey′s fibers could not be identified in the human biopsy material included in the present study.