Quantifying Periodontal Bone Loss via μCT

The animals were anesthetized with ketamine/xylazine and euthanized via transcardial perfusion using 4% PFA (4 (link)). Maxillae were hemisected and micro-focus computed tomography (µCT) images were obtained using a Siemens Inveon Micro-PET/SPECT/CT (Siemens, Ann Arbor, MI) at a 9 µm spatial resolution. Siemens Inveon Research Workplace 4.2 software was used for image acquisition and processing, 2-D and 3-D image viewing, and quantitative analysis. Unless otherwise indicated, bone loss was evaluated from the buccal side. To assess the levels of periodontal bone loss, four linear measurements were taken following 3-D reconstruction of the µCT scans. Bone loss was evaluated on the distal side of the distobuccal root of the first molar (M1), the mesial side of the mesiobuccal root of the second molar (M2), the distal side of the distobuccal root of M2, and the distal side of the distobuccal root of the third molar (M3). Unless otherwise indicated, distances from the cement-enamel junction (CEJ) to the most apical site of bone destruction were measured. Four measurements were averaged to obtain the distance from the CEJ.