Skyscan 1174 micro ct system

An accurate model of the maxillary first molar was constructed from the micro-CT images, which were acquired by a Skyscan 1174 micro-CT system (Bruker, Belgium) at resolution of 6.28 μm. The CT images were imported into Mimics software to segment the maxilla by Hounsfield values and manual mask segmentation. Three-dimensional geometry files of maxillae, teeth, and PDL were created for each mask and saved as stereolithographic (STL) files. A Computer Assisted Design software (Geomagic 12.0, Research Triangle Park, NC, USA) was applied to extract surfaces and solids from STL files. Triangle and intersection fixing techniques were performed and then Standard for the Exchange of Product model data files were created and exported separately into ANSYS 18.0 (Canonsburg, PA, USA). To simulate the experimental OTM, line pressure, which was in the position similar to the coil spring, was loaded on the distal surface of the maxillary first molar in the FE model.

We harvested calcaneuses from euthanized rat and fixed them in 10% neutral buffered formalin for 24 h. Then the calcaneuses were scanned with a Skyscan 1174 micro-CT system (Bruker, Belgium) at a resolution of 10.21 μm. The acquired axial images were imported into a NRecon and CTvox software for visualization and analysis. We defined the regions of interest as the areas proximal to the growth plate in the calcaneuses, in order to include the secondary trabecular spongiosa. BMD and BV/TV of the interested region for each specimen were also calculated by using CTAn software.

To analyze neo‐bone formation, the harvested samples were scanned by a Skyscan 1174 micro‐CT system (Bruker, Germany) at a resolution of 13 µm pixels. Visualization and reconstruction of the data were obtained using the NRecon and CTvox imaging software. Bone volume density (bone volume/tissue volume, BV/TV [%]), bone surface density, trabecular number (Tb.N; mm⁻¹), and trabecular separation (Tb.Sp; mm) were measured with CTAn software (Bruker Skyscan, Germany).