Brief communication: Bone trabeculae are visible on periapical images.

It is traditionally believed that the radiographic image of bone striae is a reflection of the trabecular pattern of cancellous bone. Results of a 1999 paper by Cavalcanti et al. contradicted this paradigm, suggesting that the intraoral radiographic image of trabecular pattern in the mandible reflects the morphology of the endosteal surface of the cortical bone, rather than that of cancellous bone. Here, we conduct a simple experiment to assess the contribution of dry mandibular cancellous bone to the image of trabecular pattern seen on intraoral films. Standardized periapical-type radiographs centered on the same region of interest of a dry human mandible were acquired before and after removal of the buccal, then of both cortical plates, together with the endosteal cortical-trabecular bone interface. One oral and maxillofacial radiologist and 4 oral and maxillofacial radiology residents blindly assessed the presence or absence of bone striations on the acquired images. We find that bone striations are visible on periapical-type images of dry human mandibles in the absence of one or both cortical plates, and that their pattern is similar to that seen in the image of the intact specimen. We conclude that cancellous bone contributes significantly to the image of trabecular bone in dry human mandibles.