Synchrotron radiation-based microtomography of alveolar support tissues

Abstract

Objectives – To study the alveolar support structures using synchrotron radiation (SR)-based microtomography with particular focus on the alveolar surface. Design – High-resolution microtomography of jaw segments of various species and subsequent three-dimensional (3D) reconstruction. Setting and Sample Population – Microtomography was performed at the DORIS-ring of the synchrotron facility of HASYLAB/DESY in Hamburg, Germany. The samples consisted of human, simian and porcine jaw segments. Results – With SR being monochromatic, no beam-hardening artifacts could occur and the grey values in the scans were therefore directly related to the local tissue densities. Apart from the mineralized tissues, the beam energy was low enough to allow for the visualization of soft tissues like the fibers of the periodontal ligament (PDL) and blood vessels. 3D reconstructions of the alveolar bone showed that it can be rough and sharply edged. Furthermore, an intricate network of marrow cavities and blood vessels penetrates its surface. Differences in the local grey value distribution in the alveolar bone pointed to remodeling activity in the close vicinity of the PDL. Conclusion – The assumption that the alveolar bone surface is smooth and continuous is not correct. This means that even small orthodontic loads can already give rise to high local stresses and strains in the bone and thus initiate remodeling processes.