After transcardial perfusion using 3.7% paraformaldehyde, the maxillae were hemisected, and micro–focus computed tomography (µCT) scanning was performed using Siemens Inveon Micro-PET/SPECT/CT (Siemens) with 9 µm spatial resolution. The linear distance from the cementoenamel junction (CEJ) to the alveolar bone crest (ABC) on the buccal side was measured (Abe and Hajishengallis 2013 (link); Xiao et al. 2015 (link)).