Granular cell tumor of the tongue in a 14-year-old girl is reported including details of studies using histopathology and immunohistochemistry. Histopathological examination revealed large tumor cells with eosinophilic, PAS positive fine granules under hyperplastic epithelium. Immunohistochemically, the tumor cells were positively stained for S-100 protein. However, immunoreactivity for Neurofilament protein and Myoglobin was negative in the present case. These findings may indicate that this tumor is a lesion of Schwann cell origin.

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We treated a 38-year-old female with unicystic ameloblastoma of the mandible conservatively. The tumor was enucleated with the dredging method. The postoperative cavity was left open and has gradually become smaller. Regrowth of the mandible occurred and the patient can live as normal a life as before surgery without any disability. Therefore, the dredging method is effective for patient with ameloblastoma of the mandible.

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The quality of the water for living in Thecho village of Nepal was reappraised for arsenic, fluorine and remaining chloride. In this inspection, we measured exact concentration of arsenic by using an atomic absorption spectrophotometer. Arsenic was not detected in any samples, although in the previous inspection using the simplified method arsenic was indicated be contained in all samples. This result indicated that water in the village was safe as for arsenic. In addition, we measured remaining chloride which was not examined in the previous inspection. Remaining chloride was not detected in city water which was treated by bleaching powder. This means that bacteria might grow easily and is a problem for which corrective steps should be taken. Furthermore fluorine was also measured exactly using an ion meter. Concentrations of fluorine in all samples were less than 0.2 mg/l. This result confirmed the previous inspection and gave the base to significance of mouth rinsing with fluoride.

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The purpose of this laboratory study was to examine seven types of rests to determine through the abutment tooth movements which type transmits forces to abutment teeth in the most favorable manner. An acrylic resin/ silicone rubber simulation model of a Kennedy class II modified 1 mandibular arch with missing teeth (right second premolar and first molars, and left first and second molars) which permitted tooth movement and ridge displacement was constructed. The behaviors of abutment teeth were measured by using digital laser displacement sensors and the measured values were reciprocally compared through the statistical analysis. The results obtained were as follows : 1) On comparing the occlusal mesial rest (design 2) and the mesiodistal rest extended to the mesial tooth (design 3) with the most basic occlusal distal rest (design 1, control), the design 2 had a tendency to be smaller, and the design 3 the smallest in inclination of the abutment tooth. Also, in twist-like movement, the designs 2 and 3 were significantly smaller (99.9 per cent confidence level) than the design 1. 2) On comparing design 4 for which the rest of design 1 was extended to mesial fossa and design 5 for which the rest of design 1 was extended to the mesial margine with the design 1, the designs 4 and 5 were significantly smaller than the design 1 in inclination and twist-like movement of the abutment tooth (p<0.001). However, an analysis of variance (95 per cent confidence level) showed no significant difference in movement between the design 4 and the design 5. 3) On comparing design 6 for which the rest of design 1 was moved to near the cervical portion with the design 1, inclination and twist-like movement of the abutment tooth with the former were significantly smaller than those with the latter (p<0.001). 4) On comparing design 7, the onlay type of rest, with design 1 in inclination and twist-like movement of the abutment tooth, the former showed significantly smaller values than the former (p<0.001). 5) On comparing with design 1, the others showed no significant difference in depression of the abutment tooth, but significantly smaller values in parallel movement (p<0.001). 6) Displacement of the abutment tooth (〓) on the non-working side was smaller than that the on the working side (〓) in all designs. On the basis of the foregoing findings, this study comfirmed that displacing the occlusal distal rest which is the typical type to occlusal mesial portion, and extending it to the mesial direction, and lowering it to near the cervical portion enabled a great reduction in inclination and twist-like movement which are said be most hazardous to the abutment tooth.

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Osteoporosis is characterized by bone component being normal but bone mass decreasing. With being aged, the absorbing function of entron and the level of bone related hormones declining result in bone mass decreasing rapidly. In our previous experiments, we studied the effects of diet therapy on bone debilitation in growth and development period, and there are few reports on diet therapy for aged bone debilitation. So in this study, we attempted to investigate the effects of calcium supplementation in combination of 1α-OH-D_3 on osteoporotic mandibular alveolus in aged rats. We used thirty 13-month-old male Wistar rats, weighing about 470 g, corresponding to aged in human. In control group, rats were fed with standard diet (Oriental Yeast, Tokyo, Japan) for 6 weeks, orally administered 2 ml/kg body weight olive oil 3 times each week. The low-calcium and calcium deficient groups were fed with low-calcium and calcium deficient diet (Oriental Yeast, Tokyo, Japan) at first 3 weeks, bone debilitation was caused by that way, and then they were fed with standard diet and 1α-OH-D_3 (Chugai Pharmaceutical, Japan) at later 3 weeks. The effects of dietary therapy and 1α-OH-D_3 on bone matrix formation were investigated, and results were as follows. I. Histopathological findings : Control group fed on standard diet exhibited dense matrix, thick cortex in both outer and inner circumferential lamellae, and well-developed Harversian systems. In contrast, reduction of osteocytic lacunae and expansion of marrow cavities were observed in calcium deficient group. Resorption and irregular distribution of trabeculae were seen also. Low calcium rats exhibited similar findings to that of control animals. II. SEM findings : Regularly distributed collagen fibrillar bundles were seen in matrix formative area and collagen fibrils were seen densely covering the surfaces of bone formation in control treatment. Lacunae and canalicali opening were distinctly observed. In contrast, absorbed areas expanded and collagen fibrils were loosely arranged in calcium deficient treatment. Collagen fibrils were seen in the upper section of bone formative areas. Low calcium rats exhibited comparable findings to those of control animals, besides collagen fibrils distributed regularly and irregularly mingled in the bone matrix. III. Hematological findings : The hematological tests were performed including serum electrolyte levels of calcium, phosphorus, ratio of calcium to phosphorus, sodium, potassium, chloride, biochemical examination of CPK, LDH, GOT, AL-P, GPT and endocrine levels of N-PTH, C-PTH, Calcition and 1, 25(OH)_2D_3. None of them has been found significant differences among the control and experimental groups. From the above results, it is suggested that bone matrix formation under calcium insufficient state could recover by diet and 1α-OH-D_3 therapy in aged rats, particularly in the low (30%) calcium group, if they had a balance diet before.

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Nitrous oxide (N_2O) has a potent antinociceptive action, The spinal Ca^<2+> channel and the intracellular signal transducing system have recently been suggested to play an important role in pain transmission and modulation. The present study was undertaken to evaluate further the involvement of the Ca^<2+> channels and the intracellular signal transducing system activity in N_2O analgesia by investigating tail-flick latency and in vitro autoradiography. Wister rats were exposed to either 70% N_2 (control) or 70% N_2O with 30% O_2 for 2 hours after staying 30 minutes in plastic box. N_2O produced analgesia : the percent maximal effect (%MPE ; tail-flick latency) increased to 79% at 30 minutes after starting of N_2O inhalation. At the end of N_2O exposure, ^<125>I-ωCgTx binding (N type Ca^<2+> channel activity) in the spiral cord (Rexed I-II) decreased by 20% accompanied by a decreased in ^3H-forskolin binding (adenylate cyclase : 22%), while ^3H-PN 200-110 binding (L type Ca^<2+> channel activity) and ^3H-GTP binding (G-protein) did not changed. These results suggest that the interactions with N type Ca^<2+> channel and adenylate cyclase in the dorsal horn of the spiral cord are involved in analgesia induced by N_2O inhalation.

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To construct the complete dentures for the efficient functioning with which the patients may be satisfied, it surely is essential to harmonize with the surrounding tissues, especially muscular tissues. We experienced two interesting cases suggestive of the importance of the harmony with the denture contours and the surrounding tissues. One was the case with the impression appearing to be affected by constriction of the mental muscle and the orbicularis had been observed at the cervical portion from the mandibular first premolar to the opposite one and the polished surface at the same area. The other was the case in which the patient was satisfied by constructing himself the polished surfaces of the maxillar denture with soft liners available in the market, after he had several practitioners make dentures dissatisfactory to him due to poor retention. In this case, however, the aesthetical problem still remained to be solved. The above two cases showed the importance of the contour of the denture, especially the polished surfaces. Therefore, their treatment method, results, and the discussion are presented in this report.

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