In vivo fluorescent images (A, B, C, and D) and hematoxylin/eosin stainings (E, F, G, and H) of sagittal sections of mandibles from 3.6Col1-GFP transgenic mice exposed to orthodontic force (C, D, G, and H) or serving as controls (A, B, E, and F). Arrows depict direction of force.