[S E M study of vascular architecture of periodontal ligament under chronic marginal periodontitis].

The present study was carried out by fabrication of microcorrosive resin cast to investigate the vascular changes of periodontium of dogs' mandibular incisors with severe mobility and deep pocket formation concomitant with suppuration and alveolar bone loss. With aid of the dissolution of soft tissues by protease, alveolar bone remained left with resin cast of specimen, which then was referred for scanning electron microscopic examination. Results were as follows: 1. The vasculature of inner gingival epithelium which originally appeared as a flat, mesh-like network underwent a conformational change and turned out to be a vasculature with glomerulus-like loops due to chronic inflammation. 2. No remarkable change was ever identified in vasculature of periodontal ligament surrounding cervix of tooth. 3. Certain parts of vasculature of periodontal ligament disappeared, which combining with the occlusion indicated the occurrence of occlusal trauma. 4. Exposed alveolar bone surface where the periodontal vasculature disappeared showed an amorphous, flat surface. Quite contrast to this, the surface of alveolar bone on which the vasculature is located appeared undergoing a resorptive process. 5. Accordingly, the damage occurred in periodontium was not merely due to chronic inflammation but to the accompanying occlusal trauma which was supposed to be a predominant factor.