Fig. 3

Light microscopic examination. Control group shows smooth boundary at the coronal (a) and apical parts (b) of the alveolar bone facing the periodontal ligament. Osteocytes are normally distributed. (H&E × 100) The alveolar crest in GOG shows apical displacement of the alveolar bone and irregularity of the alveolar bone surface and thinning of the bony trabeculae (black arrow) (c) with the apical region showing irregular bone surface with marked bone resorption. Wide bone marrow spaces with thin bone trabeculae are seen. Note the deeply stained incremental lines (white arrows). Inflammatory cell infiltrate is also evident (arrowheads) (d). (H&E × 100) The alveolar crest and middle region of the alveolar bone in ExTG show regular and smooth outline of the alveolar bone. The osteoblastic layer exhibits a regular appearance. (H&E × 100) (e). The apical region of the alveolar bone shows normal architecture of the bone surface lined by a continuous layer of osteoblast cells (arrows). Note the presence of incremental lines (white arrows). (H&E × 100) (f). AB: Alveolar bone, PDL: Periodontal ligament