Figure 1: In vivo rat ligature model for the induction of acute periodontitis. (a) Photograph illustrates lipopolysaccharide (LPS) soaked 4–0 braided silk threads in the diastemata flanking left/right second maxillary molars. Controls were flossed in the same interproximal regions. (b) Schematic illustrates the targeted regions of the fibrous joint within the study. (c) 3D tomogram illustrates the lingual-sagittal, mid-sagittal, and buccal-sagittal 2D virtual sections through a second maxillary molar used for morphometrics. Anatomical landmarks used to measure alveolar bone crest recession (CEJ-ABC) are indicated. (d) 2D virtual section illustrates anatomical landmarks to measure interradicular distance and PDL width. Division of the bone-PDL-cementum complex into coronal, middle, and apical sections for PDL-space measurements is also illustrated.