Fig. 3.

Spatial relationship between an inflammatory infiltrate and periodontal bone loss. In periodontitis, bacteria attach to the tooth surface and invade the adjacent epithelium and connective tissue. This causes formation of an inflammatory infiltrate indicated by the black arrows. If the inflammatory infiltrate is at a distance from bone (left panel), osteoclastogenesis is not stimulated. However, if the infiltrate moves closer to bone (right panel), osteoclasts are induced and bone resorption occurs.