Although it is well known that crown cusps of teeth break through the covering oral epithelium at the final stage of tooth eruption, the detailed mechanism of jts process is still obscure. This study investigated the morphological and immunohistochemical changes in the gingival and odontogenic epithelia during the late stages of tooth eruption in the rat molar, using antibodies to cytokeratin 14(CK14), cytokeratin 18(CK18), EGF receptor, p75 NGFR receptor and PCNA.Conventional H-E staining and immunohistochemistry for CK14 showed that the dental lamina for rat molars is composed of an oblique part that connects to the oral epithelium and a horizontal part that directly connects to tooth germs. The oblique part of the dental lamina did not disrupt throughout the development of molar teeth, but regressed during the late eruption period. The regressing dental lamina contained a number of epithelial pearls and few apoptotic cells. The apical portion of every molar tooth germ was combined with horizontal dental lamina with a wide transitional zone, characterized by multiple layers of cuboidal epithelial cells.The immunohistochemistry by PCNA indicated that the cells in the epithelium of the transitional zone have a higher potential of mitosis than cells in the typical outer enamel epithelium. Disruption occurred in the epithelium of the transitional zone and in the connective tissue with blood vessels penetrating into the stellate reticulum of the enamel organs during the advanced eruption stages. Epithelial cells that proliferated from the epithelium of the transitional zone extended towards the stellate reticulum layer, and formed a reticular formation of reduced enamel epithelium by fusion with epithelial cords thet proliferated from stratum intermedium cells of the enamel free area.While the reticular reduced enamel epitheliunl showed a weak EGFR-like immunoreaction, a similar structure was negative to anti-NGFR. By the final stage of eruption, reduced enamel epithelium completely fused with oral epithelium at every cusp region, and keratinization progressed not only from the outer surface but also from the inner surface in the fused epithelium. Distribution of Markel cells was investigated using anti-CK18 as the contribution of these cells in the formation of eruption passage was suspected. However, no Merkel cell was detected during entire period of tooth eruption stage.

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We studied 463 cardiovascular disease patients who were referred for evaluation and treatment of oral disease at Iwate Medical University Dental Hospita1 (IMUDH) by the Second Department of Medicine at Iwate Medical University and Iwate Medical University Memorial Heart Center from June, 1997 to December, 2000. As for cardiovascular disease, 2320f the patients (50.1%) had vascular disease, 199 patients (43.0%) hypertension, and 123 patients (26.4%) ischemic heart disease. The oral diseases of the subjects were as follows:188 patients (40.6%) had Inarginal periodontitis,106 patients (22.9%) apical periodontitis,82patients (17.7%) remaining root and 78 (16.8%) patients with dental caries. Regarding dental procedures at IMUDH,157 patients (33.9%) had their teeth extracted,120 patients (25.9%) had periodontal disease treated,106 patients (22.9%) were only evaluated and 102 patients (22.0%) were instructed in tooth brushing.243 patients (52.5%) had their dental treatment completed within 2 weeks.
An oral infection focus, such as marginal periodontitis, apical periodontitis and pericoronitis of wisdom teeth, can cause infective endocarditis or postoperative infection of cardiovascular disease.119patients (70.8%) out of 168 who were referred to us at the preoperative stage and had no oral complaint, had oral infection focus. Therefore, two thirds of the patients with cardiovascular disease in our institutions seemed to need dental procedures in order to irnprove cardiovascular treatment results.

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Narrowed dental puIp cavities and obturated root canals produced by diffuse calcification and pulp stone are often observed in advanced periodontal disease. Possibly inflammatory cytokines following periodontitis may have served as the stimulus inducing the pulp calcification, but the details are not clear.
The purpose of this study was to investigate the relation between pulp calcification and the bone morphogenetic proteins (BMPs) expressed in the dental pulp cells of advanced periodontitis cultivated in vitro, and to analyze the effect of tumor necrosis factor-α (TNF-α) stirnulation on the expression of BMPs. The calcification process of the dental pulp cells was examined by alcian blue staining, von Kossa staining, immunostaining methods (BMP-2, BMP-4, osteonectin, osteocalcin and OB-cadherin) and mapping with combined microanalyzers. The mRNA expression of BMP-2, BMP-4 and transforming growth factor-β2 (TGF-β2) was investigated by reverse transcription-polymerase chain reaction (RT-PCR) methods. Dental pulp cells formed some nodules at 4 weeks of the cultivation in the medium without ascorbic acid and β-glycerophosphate. They included alcian blue-positive glucosaminoglycans, osteonectin, osteocalcin and TGF-β2. The cells in the periphery of nodules seemed to be differentiated odontoblastic cells. The nodules showed calcification at 8 weeks after cultivation by mapping with combined microanalyzers and von Kossa staining. The nodules were positive for BMP-2 and BMP-4 at 4 and 8 weeks after cultivation. BMP-4 expression increased with TNF-α stimulation, while BMP-2 expression decreased. The results suggest that TNF-α probably serves as a kind of stimulus in dental pulp calcification of teeth with periodontitis.

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The thin HA layer that was deposited by anode oxidation and hydrothermal treatment (SA treatment) on a titanium surface, was called by a SA film.
It was suggested that the SA film was reported exhibiting bone conduction, long term stability and high adhesion strength with a titanium substrate by a study result in vivo and in vitro.
The purpose of this study was to examine the shape and crystal structure of HA in a SA film by SEM, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).
An anodic oxide film, SA film and comparison matter were measured by SEM, XRD, XPS.

From SEM and XRD, it was made clear that HA of a hexagonal system deposition on a SA film and three layers of SA film presented structure.
In the examination by XPS, the anodic oxide film moved to the low energy side and the SA film moved to the high energy side compared with HA of the comparison matter.
By XPS, it became clear that a SA film formed HA of higher crystallization than HA.

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To simulate the temporomandibular loint articular cavity irrigation, a superior articular cavity model was fabricated with ethylene-vinyl resins, based on measurements by single-contrast arthrography and the scale of the mantle tube. Experiment methods, after injection of lindigo carmine solution, the model was perfused with distilled water by the arthrocentesis (AC) and pumping lavage system(PLS)irrigation. Using particle induced X-ray emission, we quantitatively analyzed the amount of sulfur, a component element of the indigo carmine, contained in the effluent fluid and in the remaining fluid in the model. The differences in the effectiveness of the two irrigation methods were hydro-mechanically evaluated. AC was highly effective in cases in which an inflow needle was placed in the posterior compartment, an outflow needle in the anterior compartment, and the flow of the perfusate was fast;however, differences were observed depending on the position in which the outflow needle was inserted, PLS was considered to be a comparatively effective method.

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Pathological examinations undertaken in our department in 2000 were statistically reviewed.
The number of biopsy materials amounted to a total of 631 from 531 cases(255 males,276 females).Cases in the seventh decade(122 cases)were found to be the most frequently.
In histological classifications of the exarninations, there were 160dontogenic benign tumors and tumor-like Iesions. The non-odontogenic benign tumors and turnor-like lesions consisted of 32 fibrous hyperplasias,16 hyperkeratoses(leukoplakias),14 hemangiomas,8 papillomas,7 pleomorphic adenomas, 6 irritation fibromas, 6 epithelial dysplasias, 5 1ipomas, 2 1ymphangiomas. Also found were 60 cases of non-odontogenic malignant which consisted of 53 squamous cell carcinomas,3verrucous carcinomas. The odontogenic cysts included 38 radicular cysts,10 prirnordial cysts,10 dentigerous cysts and 2 calcifying odontogenic cysts. The non-odontogenic cysts included 40 mucous retention cysts(mucocele),20 postoperative maxillary cysts, and 3 incisive canal cysts.
In addition,141ichen planuses,14 Sjogren’s syndromes,13 chronic and localized hyperplastic gingivitis(epulis)were found.

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切歯が過剰歯と癒合した症例については報告されているが，複根歯の切歯やその歯周治療例にっいての報告はほとんどない。我々は，上顎中切歯で2根を有する癒合歯の歯周治療例について報告する。上顎右側切歯部頬側の発赤腫脹を主訴として来院した症例で，上顎右側中切歯は歯冠が一っであり，歯根は各々根管歯髄を有する近遠心的2根を示していた。 治療として，初期治療後，歯周外科時に遠心1根の切除と，骨欠損部へのハイドロキシァパタイトの填塞を試みた。その後，歯肉症状は消失し，治療部の歯肉は歯肉退縮をきたすことなく，当該歯を保存することができた。本症例から切歯部における複根歯の歯周治療では，臼歯部の分岐部病変における歯根の治療に準じて行う必要があるように思われた。

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片側性唇顎口蓋裂患者は手術後の上顎の劣成長により，しばしば前歯部および臼歯部反対咬合の不正咬合が生じる。そのため，我々は唇顎口蓋裂患者においては，出生直後から成人に至るまで四期に分けて非観血的矯正治療を行っている。すなわち，第一期は口唇形成手術前の患児に対して行う術前顎矯正治療や術後の顎発育の経過観察を行う時期である。第二期は乳歯咬合完成後に行う上顎側方拡大や顎発育の成長誘導の治療を行う時期である。第三期はマルチブラケット装置を用いて永久歯列の再排列を行う時期である。第四期は永久歯列の再排列後の保定と，その後の補綴治療と長期的観察を行う時期である。
今回，我々は二期から四期の19年間にわたり，著しい骨格型反対咬合の唇顎口蓋裂患者を観察し，矯正治療の効果について評価した。 患者は，初診時12歳11か月の左側唇顎口蓋裂の女子である。側貌は中顔面部が陥凹し，著しい反対咬合を呈していた。患者の動的治療期間は5年7か月であった。矯正治療により骨格的な改善は獲得できなかったが，被蓋は主に前歯の移動で改善された。19歳から32歳までの経過では，骨格的な変化はほとんど認められなかったが，前歯部の歯軸の変化が認められた。
したがって，獲得した咬合を安定させるために，さらに長期間の保定と観察が必要であると考える。

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