A study was performed to examine how the duration of irradiation at the time of relining with visible light-curing material influences the depth of hardening of the relining material, in relation to the thickness of the denture base placed between the denture and the relining material. It was found that for a range of denture base thickness of 1-2.5mm, a desirable degree of hardening could be obtained using an irradiation time of 20s for relining material with a thickness of up to 4mm used for the basal surface.

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Optimal concentrations of the essential components for analyzing the activity of each enzyme associated with glycolysis and gluconeogenesis in rabbit periodontal ligament were examined, and enzyme assay systems for 15 enzymes including 22 reactions were established using triethanolamine buffer. Specific activities of all the enzymes, except for the gluconeogenic reaction of phosphoglycerate kinase, were systematically evaluated using the optimum buffer for each enzyme, since the activity of each enzyme varied depending on the buffer used. For glycolysis, the activity levels of hexokinase and 6-phosphofructokinase were very low, and consequently these enzyme reactions were inferred to be the rate-limiting steps. For gluconeogenesis, fructose 1, 6-bisphosphatase and aldolase activities were extremely low, and the activities of glucose 6-phosphatase, phosphoenolpyruvate carboxykinase and pyruvate carboxylase were undetectable. These results suggest that the periodontal ligament may have no gluconeogenesis capability. With a rise in pH, the activities of the key enzymes of glycolysis gradually increased, and a specific “crossover” point was found between the activities of glyceraldehyde-phosphate dehydrogenase and phosphoglyceromutase. In addition, the activity of fructose 1, 6-bisphosphatase, one of the key enzymes of gluconeogenesis, was markedly increased with a rise in pH, although pH changes had no effect on aldolase activity. Consequently, alkaline pH appeared to result in overall stimulation of glycolysis.

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Of 124 patients with oral squamous cell carcinomas treated during the past 14 years, 13 developed second primary cancers with clinical symptoms in the same tissues or in organs different from those of the initial lesions during follow-up. The second primary tumors also appeared in the oral cavity in 3 of the patients, the hypopharynx in 1, the esophagus in 2, the stomach in 2, the colon in 1, the thyroid gland in 2 and the lung in 2. Of the 3 patients with second tumors in the oral cavity, 1 underwent surgery after chemo-and radiotherapy and 2 underwent laser surgery or chemo-and radiotherapy only. The second primary cancers appeared on the contralateral or ipsilateral side, completely separate from the sites of the primary lesions during a period of 1 to 3 yeares. One patient with triple cancers involving the oral cavity, esophagus and hypopharynx is still alive after 15 years. The other two patients died of cervical or lung metastases after 3 years.

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The nasopharyngeal area in 149 patients with cleft lip and palate and 157 normal individuals was evaluated by cephalometric radiography. The patients were male and female Caucasians, ranging in age from 12 to 16 years. Linear cephalometric parameters : (Ptm'-Sl ; Ptm'-IPPF ; IPPF-I, I-Ptm'), ANS angle and nasopharyngeal area were utilized. From comparative analysis of nasopharyngeal area in the cleft and the control groups, the following conclusions were made :
1) The nasopharyngeal area was smaller in the cleft group.
2) There was no correlation between ANS angle and nasopharyngeal area in either group.

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The effect of systemically administered doxycycline hydrochloride on subgingival microbial plaque morphotypes was evaluated using dark-field microscopy. After 1 week of drug administration, while the percentage of coccoid bacteria showed a significant increase, the percentages of spirochetes, motile rods and non-motile rods tended to decrease. Since spirochetes and/or motile rods are considered to be associated with the pathogenesis of periodontal disease, the significant decrease in the proportions of these bacteria are conisidered to be important. Therefore, it is suggested that doxycycline may be beneficial for the treatment of periodontal disease as an adjunct to traditional therapeutic methods.

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