Nowadays, the roll of the radiation is sufficiently recognized as important and indispensable treatment method for oral cancers. But about a half century ago, the main method for it was the surgery and the radiation took the makeshift or auxiliary method for it. The author began his clinical research work for oral cancer since 1954, under the leadership of the teachers, Ueno, T. for oral surgery and Adachi, C. for medical radiology. He'd like to write his career experiences for the development of roll of radiation by treating oral cancers. The first patient of the upper sinus cancer was treated succefully by the x-ray radiation alone, through the hard work of Nakamura, T. who was a colleague of Shimizu at the radiological Dept. in Tokyo Medical and Dental University. Shimizu examined and followed the patient in 1954 ∼ 1959 and assured the over 5 year-cure till 1962. The case brought him the true scientific surprise with pleasure. Since that time, he worked not only as oral macillo-facial surgeon but also as assistant for the radiation therapy of oral cancers till 1980 at the University Hospital of Tokyo Medical and Dental Univ.
During the forth century between 1954 and 1980, he encountered so many rare and unusual cases, which we couldn't experience in the present situation. Therefore, he hoped to let them keep in the record, through that we could open and wish the new area in the clinical field of Radiology and Surgery on the treatment and therapy for oral cancers in future.

抄録全体を表示

The demand for visiting dental care has been increasing in Japan. However, intra-oral radiographs are not frequently obtained from bedridden patients regardless of whether they are at home or in hospital. In 1998, we started a project to establish a systematic method of dental radiography for bedridden elderly. In the present study, we analyzed 60 bedridden patients receiving dental treatment and examination by intra-oral radiography between 1998 and 2000. Subjects consisted of 32 females and 28 males with an average age of 75.6 years. According to the standard for assessment of independence in daily life, 2 patients were classified in Rank J (independent in daily life activities), 3 in Rank A (house-bound : needing partial assistance only in outdoor activities), 26 in Rank B (chair-bound : needing partial assistance only in indoor activities) and 29 in Rank C (bed-bound : dependent for most daily activities). Most patients were the so-called “bedridden elderly” classified in Rank B or C. In the majority of patients (56%), the cause of becoming bedridden was cerebrovascular disease. The dental diseases were caries, periodontitis, alveolar abscess and so on. All intra-oral radiographs were taken with a portable X-ray unit and an indicators which enabled the operator to fold film and set an adequate beam projection. A total of 291 radiographs were obtained. These radiographs were retrospectively evaluated by two observers and were classified as good or poor quality. Good quality was defined as an image showing sufficient quality for clinical use. When the judgment differed between the two observers, a consensus was reached after discussion. There were no differences in the number of images obtained among Ranks for independence in daily life. The radiographs obtained in Rank C patients or in those who could not communicate with treatment staff showed poor quality. As the major cause of poor quality was failure in the holding film, improvement of the indicator was considered necessary.

抄録全体を表示

Purpose : Artifacts due to halation from an image intensifier (I.I.)/CCD system appear on limited-volume cone-beam computed tomography (CBCT). Regarding anterior tooth imaging, properties of this artifact in the geometrical relationships between field of view (FOV) and objective jaw region were studied.
Materials and Methods : A water-filled plastic cylinder was used as a phantom of the head. A test object was constructed as a bone-equivalent phantom to be imaged. The test object was set in the phantom at positions corresponding to the anterior tooth arch. Position of the test object was shifted to simulate individual variations in the thickness of the labial soft tissue. Limited-volume CBCT images were acquired using a 3DX system in the various offset FOV position. The affection of an artifact was evaluated by the size of the object's image.
Result : The position of the test object in the phantom, i.e. the thickness of the labial soft tissue contributes to the intensity of artifact. However, even when the labial soft tissue was thick, affection from artifact was prominent when the FOV was set so that the image of the test object was depicted near the margin of FOV.

抄録全体を表示

Purpose : In the present study, we investigated the influence of local irradiation to a portion of the maxilla on the numbers of lymphocyte subsets in the spleen, specifically B cell subsets (B1a cell, B1b cell and B2 cell). Five-week-old female BALB/c mice were used for the experiments. In the irradiation group, a portion of the maxilla was exposed to X-ray (2.0Gy/min, 10Gy), then lymphocytes were analyzed using flow cytometry (anti- CD23, CD5, CD45R, CD4, CD8, CD3, IL-2R β and TCRγδ monoclonal antibodies), and findings were compared to those obtained from the non-irradiation groups.
The following results were obtained : 1) B cells and B2 cells decreased significantly on the first and third days after irradiation. 2) B1a cells and B1b cells decreased significantly on the first day after irradiation. 3) CD4⁺SP T cells and CD8⁺SP T cells decreased significantly on the first and third days after irradiation. 4) γδT cells decreased significantly on the first day after irradiation. 5) int TCR cells did not change significantly after irradiation.
The above findings indicate that the cells that participate in natural immunity (B1a cells, B1a cells, γδ Tcells and int TCR cells) were less influenced by irradiation than cells that participate in acquired immunity (B2 cells, CD4⁺T cells and CD8⁺T cells).

抄録全体を表示