Histopathological Studies on Periodontal Disease

Seventy-two mandibular bones were dissected in human autopsy cases and were studied histopathologically. The age of the caces ranged from 13 to 85 years old. These involved 2 cases of gingivitis, 59 of periodontal disease, and 11 of edentulous jaw. The results obtained were as follows: 1) In the early stage of the periodontal disease, the bone resorptions were found not only in the alveolar portion but also in the corpus and the basic portion of the mandible. 2) Microscopic feature of the bone resorption was found to be of in types of smooth resorption and perforative canal formation, and the lacunar resorption type involving osteoclasts was rarely found. 3) The osteoporosis in the mandibular bone of periodontal disease seemed to increase with age, but in several cases the osteoporosis could be found in the mandibular bone of the younger individuals. 4) In almost all the cases, the inflammatory infiltration in the periodontium was recognized only in the gingiva, but in some cases the extension of inflammation from the gingiva into the periodontal membrane and the bone marrow was found. 5) The bone resorption of periodontal disease did not always occur adjacent to the inflammatory focus, and it was found in all parts of the mandibular bone in many cases. There have been reported many theories to explain the mechanism of bone resorption by the influence of an inflammatory process. The author however, recognized the fact that the periodontal disease showed the type of bone atrophy to be due to disturbances of nutrition. And so the author will present in contrast above mentioned to the theories, a new concept insisting that the disturbance of blood circulation in the mandibular arterial or arteriolar system may be considered to play an important role in the pathogenesis of periodontal disease which is characterized by bone resorption and periodontitis.