Histological analysis of the scaphocephalic calvarium. (a) The sagittal strip displays cancellous bone with variably sized osteons (white stars). Intervening medullary spaces (black star) contain typical myeloid cellular elements, but without the presence of osteoclasts. (b) The bridging bone demonstrates scattered immature Haversian systems. Areas suggestive of osteon remnants are indicated by the arrowheads. (c) An additional image through the bridging bone shows dense, confluent areas of well-formed Haversian systems characteristic of typically formed compact or cortical bone. (d) Enlarged boxed area in C shows variably sized Haversian systems of similar orientation (arrows). Portions of the image indicated by arrowheads suggest immature (woven bone) that has been replaced by newer Haversian systems resulting in the formation of compact bone.