Fig. 5. Counting of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated osteoclasts on the mesial alveolar bone surface of the distobuccal root (DBR) of the maxillary left first molar (M1), to assess the effects of nicotine on orthodontic tooth movement and bone remodeling in rats. Digital pathology software was used on identically magnifying sectioned images. A, The area for quantification (blue rectangular block on the image) includes a square with one side extending from the root apex to the bifurcation and the other side extending 200 µm from the border of the periodontal ligament inside the alveolar bone of DBR of M1. 1,000 µm (original image × 10). B, The arrows indicate each TRAP-positive multinucleated osteoclast with expressed annotations by the software. 50 µm (original image × 300).