[in Japanese]

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Male Wistar rats, 5-week-old, corresponding to humann early childhoodwere given calcium-deficient diet and calucium low-deficient diet for three weeks (group I), for five weeks (group II), and bone debility was induced experimentally. The internal structure of cortex of tibia diaphysis was then investigated. The results were as follows : I. Body weight Body weight of group I and group II decreased in order of the control, calucium low-deficient diet and calcium-deficient diet groups. II. X-ray findings on the bone density Between the cotrol groups and the calcium-deficient diet groups, between the co-ntrol groups and the calcium low-deficient diet groups and between the calcium-deficient diet groups and the calcium low-deficient diet groups, significant difference were found in medial cortex and interosseous cortex of group I and group II, and the cotrol groups, the cotrol groups and the calcium low-deficient diet groups showed higher values (p<0.01). In medial cortex and interosseous cortex, between the cotrol groups and the calcium low-deficient diet groups, significant difference were found between group I and group II and the latter showed higher values (p<0.01). III. Analysis of Ca and P on the X-ray microanalyzer In characteristic X-ray images by plane analysis of Ca and P in same trabecula of medial cortex and interosseous cortex, Ca showed higher density than P in the control group, the calcium-deficient diet groups and the calcium low-deficient diet groups for both group I and group II. IV. Histopathologic findings In the calcium-deficient diet group I as compared with the control groups, osteocytic lacunae and Harversian canal decreased, and Harversian system arranged irregularly were found scattered. In the calcium low-deficient diet groups, Harversian system increased and Harversian canal and the surrounding bone lacunae increased. In the calcium-deficient diet group II as compared with the control groups, innercircumferential lamellae were formed thick and osteocytic lacunae were poor in distribution. In the calcium low-deficient diet groups, outer circumferential lamellae and inner circumferential lamellae were seen clearly and osteocytic lacunae arranged regularly also increased. V. Scanning electron microscopic findings In the calcium-deficient diet group I as compared with the control groups, bone resportion was found extensively and was irregular in shape. The calcium low-deficient diet groups showed denser osseous layers as compared with the calcium-deficient diet groups and collagen fibrills were running regularly and bone lacunae also increased in the bone layer. The calcium-deficient diet group II as compared with that in group I showed decrease in bone construction of trabeculae, and bone resportion was found more extensively and was irregular in shape. The calcium low-deficient diet groups showed many smooth surfaces and bone construction was recognized. VI. Hematologic findings No changes at all were found in any group in electrolytes in serum or chemical examinations and normal values were shown. On the basis of the foregoing findings, durning childhood with calcium insufficiency, for the 11-week-old especially, in the calcium low-deficient diet groups, it was suggested that hormone of bone metabolism had an excellent activity; therefore, it was clear that bone construction had no differece from the control groups.

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The uncontrolled or recurrent primary lesion, and the presence of metastatic regional lymph nodes directly affect the prognosis of the cancer patients. The control of primary lesion and regional lymph node metastasis, thus, is utmost importance in achieving a high survival rate in oral squamous cell carcinoma (O-SCC) patients. Therfore, there have been several reports regarding the usefulness of clinical and pathologic parameters relating to prognosis in O-SCC patients. However, these factors predictive of prognosis have not been well described. This study is aimed to investigate the several clinical and pathological parameters in predicting prognosis in patients with O-SCC. The univariate analysis showed that the 5-year survival rates were significantly different between each strata of the prognostic factors including age, tumor size, lymph node metastasis, mitotic figures, inflammatory infiltration, necrotic tendency and vascular atach. Sex, primary site, differentiation, mode of invasion and cellular atypia did not change the survival rates significantly. In pathologic parameters, multivariate analysis using Cox proportional hazard model determined inflammatory cell infiltration, tumor invasive tendency, necrotic tendency, mitotic count and vascular attach as the significant and independent prognostic factors affecting O-SCC. The pathologic parameters including mode of invasion, cellular atypia, mitotic count, necrotic tendency and invasive tendency were correlated with the occurrence of regional lymph node metastasis. These statistical estimated prognostic factors are clinically acceptable and usefull in O-SCC.

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Tumor markers, which are tumor-mediated substances, are not specific substances directly produced by tumor tissue. The use of tumor markers has been accepted as a valuable tool for diagnosis, prognosis and treatment monitoring. Seventy-two consecutive patients with oral squamous cell carcinoma treated in our department between 1990 and 1996 were entered in the study. Blood specimens were collected after informed consent was obtained from the patients with oral squamous cell carcinoma and oral benign diseases. The results were as follows : 1. The positive rates were 31.9% for carcinoembryonic antigen (CEA), 48.6% for squamous cell carcinoma (SCC) and 58.3% for immunosuppressive acidic protein (IAP) in patients with oral squamous cell carcinoma. 2. In oral squamous cell carcinoma, there was no correlation between histological prognostic factors and CEA or SCC. 3. IAP is correlated with histological malignancy. 4. The sensitivity and accuracy of the combination assay with these three tumor markers proved to be higher than those obtained with individual markers. This combination assay was associated with histological malignancy. 5. These results suggest that evaluation of these tumor markers in oral squamous cell carcinoma is valuable in the assesment of proliferative activity and grade of malignancy.

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Calcium deficient food and low calcium-deficiency food were given for three weeks to Wistar rats of 6-week old corresponding to human school age period and to those 9-week old corresponding to adulthood, and bone debility was induced in them. Then a singular therapy with standard food containing calcium was used, and formation of bone matrix affecting the growth of cartilage of mandibular condyle was investigated. The results were as follows : I. Body weight The rats, 6-week old and 9-week old, were divided into their respective groups and maintained to 12-week old and 15-week old. As a result, no significant differences (p<0.01) were found in any group. The body weight was 6-week old<9-week old. II. Radiological findings 6-week old In the calcium deficient food group as compared with the controls, the trabeculae were found increased in the central and posterior portions but running irregularly. The low calcium-deficiency food group showed the same regularity of trabeculae as the controls. 9-week old In the calcium deficient food group as compared with the controls, the osseous layer was uneven in thickness and the trabeculae were running irregularly. The low calcium-deficiency food group showed about the same findings as the controls. III. Findings on Ca and P analysis on the X-ray Microanalyzer Relative Ca ratio and P ratio were determined by quantitative analysis by point analysis. 6-week old The controls and low calcium-deficiency food group showed about the same relative Ca ratios, but the calcium deficient food group showed low values. Relative P ratios were in the order of the low calcium-deficiency food group>controls>calcium deficient food group. 9-week old Relative Ca ratios were in the order of controls>calcium deficient food group=low calcium-deficiency food group. Relative P ratios were in the order of controls>low calcium-deficiency food group>calcium deficient food group. IV. Histopathological findings 6-week old In the calcium deficient food group as compared with the low calcium-deficiency food group, chondroclasts were restricted in the hypertrophic chondrocyte layer, and intrachondral ossification directly below the invasion zone was decreased. 9-week old In the calcium food group as compared with the controls, intrachondral ossification was restricted. In the low calcium-deficiency food group as in the controls, calcification of the matrix in growing chondrocyte layer was progressed and growth of the mandibular condyle by the mechanism of intrachondral ossification was seen. V. Hematologic findings 6-week old and 9-week old No changes were found in electrolyte in blood serum and in biochemical examinations in any group. Comparison between 6-week old and 9-week old K was high in value (p<0.01) for 6-week old in the low calcium-deficiency food group. Cl was high in value (p<0.01) for 6-week old in the controls and calcium deficent food group. CPK was high in value (p<0.01) for 9-week old in all groups. ALP was high in value (p<0.01) for 6-week old in all groups. On the basis of the foregoing findings, growth of the cartilage of mandibular condyle is affected by insufficient intake of calcium in the growing stage. In the low calcium-deficiency food group especially, findings of recovery of formation of bone matrix related to growth of the cartilage of mandibular condyle were evident.

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The changes in the number of AgNORs per nucleus in normal cells are obscure. In the present study, we examined the variability of AgNORs in osteoblastic MC3T3-E1 cells. We designed to enumerate the number of AgNORs during cell differentiation. The cells were grown for up to 20 days in the presence of fetal bovine serum. At the days 3, 6, 9, 13 and 20 after plating, the cells were stained by AgNOR method and also used for measurement of ALP activity. The number of AgNORs per nucleus increased from 6.9±2.15 (at the day 3) to 11.7±2.79 (at the day 6), decreased to 7.9±2.25 (at the day 9) and then leveled to 7.7±2.19 (at the day 20). The ALP activity was maximal at the day 9 after plating. In osteoblastic cells, the number of AgNORs was maximized in the earlier matrix maturation stage, not in the proliferating stage and was variable during cell differentiation.

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In August and September of 1995 the author conducted an anthropometric examination of the head and face, and measurement of the dental arch on Hui tribe (81 males and 87 females), inhabitants of Shen Yang City. Furthermore, the correlations between the measurements of head and face, and those of dental arches and palate height were studied. The results obtained in this study were as follows : 1) Head length : The mean value for the male is 183.3 mm and for the female 174.1 mm, both of the Middle Type. 2) Head breadth : The mean value for the male is 156.7 mm and for the female 152.2 mm, both of the Wide Type. 3) Bizygomatic breadth : The mean value for the male is 138.1 mm and for the female 134.1 mm, both of the Middle Type. 4) Morphological facial height : The mean value for the male is 121.3 mm and for the female 115.4 mm, both of the High Type. 5) The head-type of the Hui tribe is of Hyperbrachycephalic Type and the face-type to Mesoprosopic Type. 6) Correlation : For male no significant correlation was found between bizygomatic breadth and upper dental arch breadth or between bigonial breadth and lower dental arch breadth. But significant positive correlation was shown in the head height and palate height. In female, no significant correlation was found between morphological face height and palate height or between bigonial breadth and lower dental arch breadth. But significant positive correlation was shown in the head breadth and upper dental arch breadth.

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The morphology of lower molar teeth (rootless drycodont tooth type) of Japanese field voles was examined histologically. The results obtained were summerized as follows. 1. The dental formula of Japanese field vole was shown as follow : I 1/1 C 0/0 P 0/0 M 3/3=16 Of the molar teeth examined, the M_1 (1st molar) was the largest in size and molars gradually decreased their size as tooth positioned distally. 2. M_1, M_2 (2nd molar) and M_3 (3rd molar) were continuously growing teeth and their occulusal surfaces were completely flat, which were characteristics of drycodont type. 3. M_1 was composed of five lobes. M_2 and M_3 were composed of three lobes. 4. In M_1, the proximal portion of the 1st lobe and the lingual and buccal portions of the 5th lobe lacked the enemel layer. In M_2 and M_3, on the other hand, the proximal portions of the 1st lobes and the lingual and buccal portions of the 3rd lobes lacked the enemel layer. 5. Grooves between lobes were filled completely with filling cementum. 6. Formation of filling cementum began to start from each proximal portion of lobular grooves. 7. Filling cementum usually consisted of the cellular osseous cementum, but the cementum showing characteristics of the cartilage-like cementum or vasocementum was also observed occasionally. 8. Two types of pericoronal cementum, i. e., acellular pericoronal cementum covering the enamel surface and cellular pericoronal cementum covering directly the dentin at the enemel free areas, were observed. 9. Morphology of the cellular pericoronal cementum contained many cementum corpuscles and resembles that of secondary cementum of the rooted teeth. 10. It was suggested that cellular pericoronal cementum of Japanese field voles was highly adapted structures for masticatory pattern of herbivores.

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Matrix vesicles are extracellular organelles that initiate mineralization in the extracellular matrix of various calcifying tissues. It is generally accepted that matrix vesicles arise by budding and pintching off from the cell membrane and therefore matrix vesicles contain a high level of alkaline phosphatase (ALP). In recent years, lactate dehydrogenase (LDH) isoenzymes were found to be located in matrix vesicles of epiphyseal growth plate of young rabbit leg bone and metalloprotease in matrix vesicles of chicken epiphyseal cartilage. On the other hand, calcification of the trachea cartilage has been reported although it was once accepted to remain as a permanent hyaline cartilage without calcification. In the present study, properties of matrix vesicles in the trachea cartilage of fetal bovine were compared with those in the epiphyseal cartilage of tibia in 2-month-old fetal bovine. 1. Only the matrx vesicles with ALP, LDH, and metalloprotease were present in the epiphyseal cartilage of tibia. In contrast, there were not only the matrix vesicles but also matrix vesicle-like vesicles with a high density in the trachea cartilage ; the vesicle contained ALP and LDH but did not metalloprotease. 2. Aldolase, aspartate : 2-oxoglutarate aminotransferase, alanine : 2-oxoglutarate aminotransferase, cytosolic enzymes except LDH, were not detected in these vesicles. These results suggested the presence of mechanism for the specific uptake of cytosolic LDH. 3. The electrophoretic LDH isoenzyme patterns differed between the matrix vesicles and the matrix vesicle-like vesicles in the tracheal cartilage. 4. There were also not only the matrix vesicles but also matrix vesicle-like vesicles with a high density in the 5-month-old fetal trachea cartilages.

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The morphology of lower molar teeth of Bedford's red-backed vole, Clethrionomys rufocanus bedfordiae, was examined histologically, and following results were obtained. 1. The formula for the dentition of this animal was written : 1 1/1 C 0/0 P 0/0 M 3/3=16 2. The crown of the first molar (M_1) was the largest in size, composed of four lobes. The crown of the second (M_2) and the third (M_3) molars was composed of three lobes. Each lobe was divided from adjacent lobes by a large indentation. 3. Each lobe consisted of greater part of dentin, which was covered by the enamel except for the proximal portions of the 1st lobes (M_1, M_2, M_3) and the lingual and buccal portions of the 3rd (M_2, M_3) and the 4th (M_1) lobes. 4. A large indentation (a groove) between neighboring lobes was filled with filling cementum, which was rich in blood vessels and was regarded as a type of vasocementum. 5. Pericoronal cementum, covering directly the dentin at the enamel free area, was relatively thick and occasionally contained well-developed cement corpuscles. 6. Each molar tooth had two roots, one proximal root and one distal root. In M_1, the proximal root arose from the 1st and the 2nd lobes and the distal root arose from the 3rd and the 4th lobes. In M_2 and M_3, the proximal root arose from the proximal lobe and the distal root arose from central and distal lobes. 7. The ratio of the length between the crown and the root was approximately 1 : 1. 8. M_1, M_2, M_3 were rooted teeth, but their root tips were not fully developed even in adult animals. 9. From the present findings, it was considered that lower molar teeth of Bedford's redacked vole might belong to the category of semihypsodont teeth, close to those of mongolian gerbil, Meriones unguiculatus.

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By observing the movements of abutment teeth with Akers clasp, back-action clasp, single and continuous Konus-type attachments in Kennedy class I case with loss of the first and second molars, which occures more often in the clinically, evaluated the design advantages and the drawbacks in relative sense with the judgment standard of the anatomy characteristics periodontal ligament from the movements of abutment teeth. The displacements of abutment teeth were measured using six displacement sensors for three axes when two types of test food particle (short and long food particles) were crashed, and analised the valid differences with t-test. The results obtained from the simulation model were summarized as follow. There were four types of movements -parralel movements, inclinations, twist-like movements and depressions- on the abutment teeth in this situation. 1. Parallel movements : There was almost no displacement for buccolingual, the clasp group showed the distal and Konus-type group showed the mesial large movement. 2. Inclinations a) In different from the parallel movement, the buccolingual displacements were mainly occured rather than the distal movement, inclinated to the lingual direction with slightly tilted distal. b) The difference of the magnitude of inclination was recognized almost none at the non-working side, but the inclination of the clasp group at the working side was significantly greater than that of the Konus-type, and the magnitude of inclination of the abutment tooth (5^^-) had a tendency to be greater than that of 4^^- in design K1. 3. Twist-like movements : In either the clasp design, twist-like movements were very little, but the twist-like movement barely recognized was observed at the working side of the clasp design B and the non-working side of K1. 4. Depressions a) In vertical displacements, both side abutments did not moved to up ward, but only to down ward. b) There was very small difference among each design, however, the maximum accelerated occasion, the working side support showed the larger depression in the order of K2, clasp B, A, and K1, although was slight. c) Overall, the depression rate of the non-working side support was some one-third to a half of the working side support. 5. Mechanical properties of each design : With the maximum load of the 7 kilograms, the design showed the largest inclination inside the working side support was B, followed by A, and clasp group, and those showed the larger movement than Konus-type gourps of K1 and K2. As you can see above, when the designs used in this experimentation are used in the bilateral, the danger of the distal inclination as mentioned before is very slim. Therefore, the need of the stress breaking system is very small.

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The region of the mid-dorsum of the tongue is the preferred site of Median Rhomboid Glossitis (M. R. G.). At present, two theories, a developmental anomaly and inflammatory reaction, are mainly mentioned concerning the etiology of the M. R. G., whereas the absolute cause is unclear. There were four thousand cases in Kyushu Dental College Hospital from 1987 to 1996, but only three cases were diagnosed as M. R. G.. Histologically, Candida hyphae existed in the parakeratinized layer and lymphoplasmacytic infiltration was present in the lamina propria. These findings demonstrated that the etiology of the M. R. G. is a localized chronic Candida infection, not only a developmental anomaly.

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