I observed 252 patients with postoperative maxillary cysts clinically and with the scanning electron microscope. Forty-nine cases of the cysts that were closely related to the teeth were further divided into three types based on clinical findings. Type 1 was designated as the postoperative radicular cyst, and had apparently healthy, pulpless roots penetrating the cyst. The cyst formation of this type is believed to occur from pulp necrosis caused by apical root injury at the time of radical surgical procedures for maxillary sinusitis. The necrosis leads to apical periodontitis, apical granuloma, and finally development of the radicular cyst. Ninety-six latent cysts(45.7%)which were clinically silent were found contralateral to the side of the operation. Five of these were surgically treated. Fluid aspirates taken from 4 of the cases were all viscous and represented mucinous secretions. The presence of the ciliated cells was confirmed in all cases observed by scanning electron microscopy(SEM). These findings suggest that some cases of the latent cysts develop into apparent cysts. SEM observation of the surface patterns of 80 cysts were carried out and the epithelia was classified into 5 types based on the number of ciliated cells. Type 1:abundant ciliated cells, type 2:moderate ciliated cells, type 3:sparse ciliated cells, type 4:no ciliated cells, and type 5:no epitheleum. Although ciliated cells were present in 57 of the cysts, there were large variations in their number. Several theories has been proposed to explain the development of the postoperative maxillary cyst. This study seems to indicate that the sinus obstruction theory is the most probable for unilocular cysts, although it does not explain multilocular cysts. Obstruction between the cystic wall and nasal cavity, and the presence of ciliated cells on the cystic wall are important in the sinus obstruction theory.

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Although there has been increased use of propofol for sedation during dental treatment, there have been few reports on its effect on the central nervous system. I used microdialysis to examine the effect of propofol on dopamine metabolism in the rat prefrontal cortex to study its influence on the central nervous system. Rats were anesthetized and a microdialysis probe was implanted into the left prefrontal cortex. After one week, Ringer's solution was perfused in the probe at a flow rate of 2μL/min, and samples were collected every 20 minutes. Samples were then injected immediately into a high performance liquid chromatography system with an electrochemical detector. The dopamine level of the rats receiving physiological saline was significantly increased with the noxious stimulation compared with the animals that did not receive noxious stimulation. The dopamine level of the rats receiving propofol was significantly increased with noxious stimulation compared with those receiving physiological saline. Administrating both propofol and bicuculine with noxious stimulation did not significantly change the dopamine level. Bicuculline significantly antagonized the effect of dopamine release under noxious stimulation with propofol. These results suggest that the effect of propofol might be related to the GABAA receptor.

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We investigated the relationship between the expression pattrn of α-catenin using western blot analysis and prognosis in 78 patients with primary oral squamous cell carcinoma. We found that reduced expression of α-catenin occurred more frequently in the patients with clinical lymph node metastasis compared with non-metastasis. Moreover, reduced α-catenin expression closely related with shorter patient survival. Determination of α-catenin expression in oral squamous cell carcinoma is therefore expected to provide useful information with regard to prognosis.

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I investigated the use of molecular biology for the prognosis of oral cancer. To date, a significant number of protein and DNA markers have been explored using immunohistochemistry, polymerase chain reaction(PCR) related techniques, and flow cytometry. Some of the most important markers studied include oncogenes(myc, ras, cyclin D1, erbB2, bcl-2), tumor suppressor genes(p53, Rb), growth factors related factors(Ki-67, PCNA, AgNORs, BrdU), loss of heterozygosity at various DNA loci, human papilloma virus(HPV), and telomerase. I researched detection methods such as DNA microarray, microdissection and in situ PCR. This presentation discusses the potential clinical utility of these markers and methods, and the future directions of study.

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I carried out clinical, radiographic and histologic investigations on the effect of the induction therapy of simultaneous combination of external radiotherapy, chemotherapy using Bleomycin(BLM) or Peplomycin(PEP) and surgery for squamous cell carcinoma of the mandibular gingiva. The induction therapy generally included a total radiation dose of 30 Gy given in 15 fractions over 3 weeks together with intravenous injections of either a total BLM dose of 90 mg given in 6 fractions, or a total PEP dose of either 45 mg given in 9 fractions or 60 mg given in 6 fractions. This therapy seemed effective as a preoperative treatment for mandibular gingival carcinoma because it resulted in long-term remission of the tumor in many cases, even when used alone without adjunctive treatment. This effectiveness was confirmed in the histological examination of resected tissues. Precise preoperative imaging should be performed to determine the extent of tumor invasion in the mandible. When the mandibular canal has been invaded by the tumor, it must be excised to prevent tumor extension along the mandibular neurovascular bundle.

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Because the oral and maxillofacial region is concerned with articulation, swallowing, mastication and esthetics, excision of oral cancers can have a large impact on function and cosmetics, thus affecting the patient's quality of life. Oral reconstruction is designed to restore function and esthetics, thus permitting surgical resection in cases of advanced oral cancers. However, an accurate, objective postoperative evaluation of these problems is often not done. I would like to explain the techniques of oral reconstruction, and the results of our investigations into speech intelligibility following glossectomy.

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I investigated the effectiveness of radiation combined with peplomycin as an induction therapy for carcinoma of the oral cavity. In addition, we treated patients with squamous cell carcinomas of the tongue by interstitial brachytherapy alone or in combination with external radiation at the Department of Radiology, Osaka University Medical School. Combining radiation with peplomycin improved treatment outcomes for carcinomas of the gingiva and mucosa. In particular, a regimen of 40 Gy radiation plus 40 mg peplomycin as an induction therapy appears promising as a conservative form of radical treatment, as it does not induce a severe acute mucosal reaction. High dose rate interstitial brachytherapy was found very effective for patients with carcinomas of the tongue at stages T1 and T2, and for superficial lesions.

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In the surgical treatment for oral cancer, the postoperative defect in the jawbone occurs in a lot of case. As the result, various dysfunction occurs in the oral main function of speech, chewing, swallows, etc... And the aesthetic disorder is generated in the case with deformation of the complexion. For the dysfunction, the maxillofacial prosthesis is applied to recover them. In the many dysfunction observed to the maxilla maxillary prosthesis patient, they are result of originating from palate division closure disorder by maxilla parenchymatous defect and result of originating from the deformation of the complexion. In case of the lower jaw maxillary prosthesis patient, there are many results of originating from jawbone defect and jaw shift with it and movement disorder of the tongue. There is a purpose of the rehabilitation by the maxillary prosthesis thing for improvement and recovery of the superscription dysfunction. If the simple expression is done, to have a meal with ordinarily relish, to have ordinarily conversation, and to be able to go to eat out to anywhere is the purpose of the rehabilitation by the maxillary prosthesis.

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We tested 28 materials for estrogenicity using three in vitro bioassays. Several of these were dental materials and the others were bisphenol-A-related chemicals. Bisphenol-A(BPA), bisphenol-F(BPF) and bisphenol-A-bischloroformate(BPACF) showed estrogenic activity by the yeast two-hybrid system, and BPA, BPF, BPACF and bisphenol-S(BPS) showed estrogenic activity by the fluorescence polarization system. However, none of the remaining chemicals and none of the dental materials showed any activity at concentrations between 10^<-3>M and 10^<-7>M. Although BPA, BPF, BPACF, bisphenol-A-dimethacrylate and BPS showed estrogenic activity by MCF-7 cells in the E-screen test, the remaining chemicals did not. Further studies should be done on the relationship of structure and activity, and on the in vivo activity of the materials.

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