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松本歯科大学病院矯正科における20年間の来院患者の実態調査 : 1972年～1991年
Get PDFapplication/pdfA statistical observation taken from 2843 patients (1972-1991) of the Department of Orthodontics, Matsumoto Dental College Hospital was performed. The results were as follows; 1. The number of the patients each year increased and peaked in 1982. Since that time almost no change in number was observed. 2. The ratio between males and females was 1 : 1.8. Particularly, the rate of teenage female patients, and the rate of the male patients in twenties and thirties were higher than the average rate. 3. Analyzed by age groups, 77 percent of the patients were of primary and junior highschool age. Patients over eighteen years of age comprised 15 percent of the total. 4. The incidence of malocclusion was highest in the mandibular protrusion, crowding and maxillary protrusion were second and third, respectively. In particular, crowding cases were comparatively high in females. At the conclusion of this study, it was seen that the rate of mandibular protrusion showed decreasing tendencies while crowding showed increasing tendencies.journal articl
下顎骨連続離断術後に発症したガス壊疽の1例 : 発症初期の臨床所見を中心に
Get PDFapplication/pdfGas gangrene in the head and neck is sometimes seen in progressive odontogenic infection. If it is not correctly diagnosed and treated in its early stage, it results in death. However, diagnosis in the early stage is very difficult because of its rapid sequence. We report the course of a case of a gas gangrene followed by partial mandibular resection for the ameloblastoma and reconstruction by using iliac bone graft. The patient was a 48-year-old man with no history or evidence of immunocompromising disorders. Although antibiotics were prescribed, gas gangrene was found at four days after the operation and CT scan revealed gas bubbles around the grafted bone, the mandible, the platysma muscle and the masseter. If the initial clinical signs were not specific for gas gangrene, the diagnosis might have been delayed without CT scan. However, decrease of the leukocyte and erythrocyte counts were found in this case. Leukopenia may occur due to convergence of granulocytes to the affected area. If this is seen frequently in this disease, these counts may be useful in diagnosing gas gangrene following operations of the head and neck, and not only radiologic findings but laboratory evidence may be important for its diagnosis.journal articl
骨粗鬆症の診断への顎口腔領域からのアプローチ
Get PDFapplication/pdfIn order to make the diagnosis of osteoporosis or to know the risk of fracture, radiographic images are one of the best media. Among many radiologic methods for detection, conventional radiographs are the most practical method by which bony structures are evaluated qualitatively for diagnosis. Recently, Quantitative Computed Tomography (QCT) and Dual Energy QCT (DEQCT) have made it possible to measure the bone mineral density (BMD) quantitatively for the accurate diagnosis and the estimation of fracture risk. Many studies have been done on the radiological approach to the mineral content of mandibular bone, excessive resorption of alveolar bone, and other oral findings. However, there have been some difficulties in the evaluation of these oral findings, especially in the measurement of bone mineral contents due to the characteristic features of this region. In 1992, Taguchi established the measurement method of BMD of the mandible using DEQCT, and found the high correlation between the BMD of mandibular cortex and that of lumber spine spongiosa. The latter is also higly related to the mandibular cortex width (MCW) just below the mental foramen in rotationary panoramic radiograph. Tooth loss was proven to be another oral sign. MCW in women with 14 or fewer teeth shows rapid decrease from the fifth to seventh decade of life. In seventh decade, MCW for those with 0 to 14 teeth is significantly lower than that for those with 15 to 28 teeth present. Although excessive resorption of alveolar bone and chronic destructive periodontal disease have been thought to be the possible oral signs of osteoporosis, they have not been thoroughly investigated yet. Consequently, BMD of the mandible, MCW and tooth loss are the indicators or oral signs of osteoporosis in the elderly, which might contribute to the early detection and control of this pathosis.journal articl
中国石家荘市小児の乳歯列形態 第二報 : 下顎乳臼歯歯冠形態の調査研究
Get PDFapplication/pdfIn order to investigate the arch dimensions of deciduous dentition, as well as the condition of primary occlusion and crown morphology of deciduous teeth in Chinese children, dental checks and impression of dental plaster models were performed at nursery schools in Shijiazhuang, China. The authors previously reported the deciduous arch dimensions in Chinese children. Based on the same dental plaster models, we conducted the present study was to investigate the crown morphology of mandibular deciduous molars in Chinese children and to compare it with those previously reported for different races. The results were as follows: 1) Regarding the occlusal surface pattern of m_2, 95.1% were type Y and 4.9% were type +; no type X patterns were observed. Sixth cusps were noted in 29.4% of m_2, and seven cusps in 45.1%. 2) Regarding the occlusal surface pattern of m_1 85.7% were type Y, 2.9% were type +, and 11.4% were type X. Among these teeth, 50.5% had four cusps and 49.5% five cusps, and no teeth with six cusps were observed. 3) The frequency of Protostylid on m_2 was 46.5% and the developmental state of the Protostylid was rudimentary in 70.8%, distinct in 23.1%, and well-developed in 6.2%. 4) The frequency of Cingulum on m_2 was 55.3%. 5) For the ratio of anterior and posterior occlusal measurements of nil no significant difference observed between the Chinese children and Japanese children in Hanihara; the index was 49.9 or less in 16.9%, between 50.0 and 67.0 in 64.8%, 67.1 or more in 18.3%.journal articl
Preliminary Report on the Jaw Tracking System with Six Degrees of Freedom (MM-JI-E, Jaw tracking system)
Get PDFapplication/pdfThe purpose of this study was to quantitatively analyze the mandibular movement by the Jaw tracking system with six degree of freedom (MM-JI-E). Displacements of the condyles under maximum clenching with successive loss of mandibular supporting zones were measured. The patient, a 29-year-old man, had been treated at an orthodontic clinic between 1994 and 1997, and temporary full coverage crowns were fabricated on four molars of the lower jaw. He showed no signs of abnormality of stomatognathic function. We measured the jaw movements with MM-JI-E, removing the crowns from the distal end of molars to the mesial. The condylar displacement values were displayed and calculated by the measurement of mandibular movement. When the supporting zones were reduced successively, both condyles moved upwards and slightly forwards (87-117°). The maximal condylar displacement values was 700μm without any support in the molars. We compared the measurements of MM-JI-E with those obtained with another jaw movement tracking system (Bio Pack), with three degree of freedom. The maximum opening paths in sagittal border movement were compared for the two measurement systems. The Bio Pack showed the deflection of the path of anterior maximum opening due to electronic error.journal articl
