Figure 1. Microradiographic and histological presentation of periodontal tissues, namely, the tooth root surface (cementum), marginal gingiva, periodontal ligament, and alveolar bone. Microradiographs of cross-sectioned mandible in the molar region showing (A) normal alveolar bone (N = no bone loss), or (B) where moderate alveolar bone loss (V) can be observed (white arrows) without loss of bone crest. Bars = 1 mm. (C) Histological section of periodontal tissue showing typical alveolar bone resorption (R+white arrows), indicating pits of bone-resorbing sites, on the inner aspect of alveolar bone (next to periodontal ligament). D, dentin; AB, alveolar bone. Bar = 100µ.