[Clinicopathological studies on localized cemento-osseous dysplasia of the jaws].

The aim of this study was to clarify the entity of localized cemento-osseous dysplasia (COD), which occurs mainly in the posterior mandible. The clinical, radiographical, and histopathological features of 51 patients with COD were retrospectively studied. Radiographic features of the COD were classified into four types, according to the appearance of calcified bodies with related teeth and without related teeth. Pathological features of the COD were classified into four grades, based on the maturation of cemental masses. The results are summarized as follows: 1. Forty-four (86%) of the 51 patients were women. The mean age of the total group was 52.5 years, and 98% of COD lesions occurred in the posterior mandible. Clinical symptoms of COD were significantly more frequent in cases without related teeth (87%) than in cases with related teeth (55%). 2. The radiolographical calcification of COD was not related to the mean age, but it was related to the grade of histopathological maturation. 3. The four progressive stages of COD were recognizable both radiographically and histopathologically. The early stage is the osteolytic process, the intermediary stage is the cementoblastic process, the mature stage is the cementosclerotic process, and the end stage is necrotization of the cemental mass. These results suggested that localized COD in the posterior mandible had progressive stages both radiographically and histopathologically. The entity of localized cemento-osseous dysplasia was identified with focal cemento-osseous dysplasia, which was reported by Summerlin and Tomich.