全身麻酔下集中治療児の環境調査

To investigate positive inhibitory measures against severe caries thought to develop in nursing infants, we examined the nursing environment of intensive care infants under general anesthesia at Matsumoto Dental College\u27s Department for dental treatment from January 1989 through December 1993

Pathological Examination of Experimentally Induced Periodontal Polyp in Mice

The mechanism in the formation of periodontal polyp has been established in several histological studies but details on cell differentiation and/or proliferation have not been elucidated. In the present study, we established a convenient and possible experimental system using ddY mice. Briefly, pentobarbital sodium (Somnopentyl) was injected into the abdominal cavity of the mouse followed by access cavity preparation on maxillary first molar using low speed ½ round bur (Merufa Inc), exposing the pulp and then allowed to perforate the floor of the pulp chamber. Observation was done over time until 6 months using micro CT (m_CT) image photography. Results with transmission image using m_CT showed theexpansion in the width of the periodontal ligament in the furcation area. The lesion was excised as one mass and examined histopathologically. The granulation tissue was covered with stratified squamous epithelium. The present experimental technique has been confirmed to be effective in analyzing the formation of periodontal polyp induced by mechanical perforation

Reactions to Bioabsorbable Suture Thread Embedded in Rat Subcutaneous Tissue

We examined the subcutaneous tissue reactions in rats to bioabsorbable suture thread using histopathological methods. Using Wister rats, Vicryl®, a bioabsorbable suture thread, was embedded into the subcutaneous tissue and histopathological examination was carried out after 4 weeks. Cholesterin crystals were used for the control. Furthermore, immunohistochemistry for CD68 was done. Histopathological examination showed proliferation of granulation tissues inboth experimental and control groups. The majority of cells in the granulation tissues were macrophages and giant cells. Fibroblasts were also observed in the proliferating granulation tissues surrounding the embedded bioabsorbable suturethread. Immunohistochemistry revealed that macrophages and giant cells were positive to CD68. The results suggest that the embedded bioabsorbable suture thread is not only fabricated to undergo absorption but also for phagocytosis bymacrophages and foreign body giant cells

下顎第3大臼歯の萌出程度と下顎骨の形態について

Recent studies have indicated that even in cases in which the existence of tooth germs are observed, third molars cannot perfectly erupt because there is too little space for eruption in the distal end of the 2nd molar, and that cases of impaction or semi-impaction are increasing. The purpose of this study was to compared the morphological variation of the mandible as the mandibular corpus and the mandibular ramus among three groups: a group of full impaction of the third molar in the mandibular dental arch (A group), a group of semi-impaction (B group), and a group of full eruption (C group). The following results were obtained. 1) Concerning the measurements representing distance: R (the width of the mandibular ramus), was significantly longer in group A while it was shorter in group C. M (total length of the mandible), C (length of the mandibular corpus) and the distance between Cd and Gn were all significantly longer in group C than in group A. 2) Concerning the measurements representing angles, the Go angle was significantly larger in group C than in group A. 3) All the measurements in group B approached the median value of those of group A and group C. It was suggested that there was no impaction of the mandibular third molar observed due to the reduction of the mandible, and that the eruption of the mandibular third molars appears to be affected by the growth and change in the mandibular corpus and the mandibular ramus and/or the change in the Go angle

Size and Morphology of Sella Turcica in Malay populations: A 3D CT Study

The purpose of this study was to analyse the linear and area dimensions and morphological shape of sella turcica to determine if differences exist due to gender or age and compared with available global data. A total of 183 (113 men and 70 women) Malay subjects who had their computed tomography (CT) scan at the Radiology Department, Hospital University Sains Malaysia (HUSM) for ordinary diagnosis not related to craniofacial deformities. The selected age groups were divided into four groups as children (0-6 years), preadolescents (7-12 years), adolescents (13-20 years) and adults (21-35 years). The images were processed using Mimics V17.0 software. Conventional measurements included three different heights of the sella turcica (anterior, posterior, median), its length, diameter, area and width, measured in relation to the Frankfort reference line (FH). Morphometric methods were used to assess shape. No significant differences in size of the sella were found except at sella height anterior between genders. When age was evaluated, significant differences were found among all age groups. The study found that sella turcica presented with a three different shapes: in a U shape (57.9 %), in a J shape (24.5 %) and shallow (17.5 %). Sella shape and dimensions reported in the current study can be used for discovering Pathological enlargement of the pituitary fossa and may also be helpful in providing reference data in the assessment of racial, gender and age specific variation in Malay populatio

マウスにおける実験的根尖部炎症病変の確立

Abstract: Although studies on the formation of apical periodontitis have somehow been carried out but detailed cellular dynamics remain unclear. We recently established an experiment that could easily be performed using ddY mice. First, under general anesthesia using isoflurane inhalation, the coronal portion of the maxillary first molar was penetrated using a round bur and drill with water irrigation causing pulp exposure until the root apex. Micro computed tomography (R_mCT) was taken over time during observation. Four weeks later, R_mCT confirmed the presence of a radiolucent image at the apex of the tooth, which was then removed for histological examination. The results showed that granulation tissue with fibrosis had gradually formed at the periphery of the abscess. The present method confirmed the effectiveness of the experimental mode to exmine the formation of chronic inflammatory lesions at the root apex.根尖部炎症病変のマウスモデルを作製した。マウスをイソフラン吸入により麻酔し、上顎第1大臼歯の歯冠部をラウンドバーにより貫通させた後、水の灌注により穴をあけて根尖まで歯髄を露出させた。処置の4週間後、根尖部にX線透過性部位が存在することが、マイクロコンピュータートモグラフィーにより確認された。この部位について組織学的検査を行った結果、線維増生を示す肉芽組織が膿瘍の周辺に徐々に形成されることが明らかになった。以上より、本モデルは根尖部の慢性炎症病変の形成を調べる上で有用であることが示された

Bone Marrow Mesenchymal Cell Contribution in Maintenance of Periodontal Ligament Homeostasis

In general, remodeling phenomenon of the periodontal ligament (PDL) is occurring in all times. Thus, in the chapter, the word “maintenance” was used, and the chapter title is “Maintenance of Periodontal Ligament Homeostasis.” Our experimental data on the remodeling of the PDL with cell acceleration at the furcation area in this experimental model are recovered using the cells in situ and the bone marrow-derived cells (BMCs). BMC migration into the PDL tissues using green fluorescent protein (GFP) bone marrow-transplanted model mouse was examined. BMCs have abilities of cell migration and differentiation into tissues/organs in the body. The immunohistochemistry revealed that GFP-positive cells were detected in the PDL. GFP-positive cells were also positive to CD31, CD68, and Runx2 suggesting that fibroblasts differentiated into osteoclasts and tissue macrophages. In this way, Notch signaling involvement considered in our tentative examinations revealed that the experimentally induced periodontal polyp was examined; the cytological dynamics of the cells in granulation tissue are mainly from migration of undifferentiated mesenchymal cells of the bone marrow and differentiate into the tissue-specified cells. Furthermore, the data suggest that cell differentiation is due to Notch signaling

松本歯科大学病院における小児全身麻酔下集中歯科治療の検討 : 過去11年間の環境要因の変遷について

We investigated the actual child-rearing environment, considering factors such as hygiene training, among 177 children (102 boys, 75 girls) ranging from 1 year and 9 months to 7 years and 2 months in age who underwent intensive dental treatment under general anesthesia in the Department of Pediatric Dentistry, Matsumoto Dental University Hospital between January 1990 and December 2000. The following results were obtained. 1) The annual number of patients slightly increased between 1992 and 1994. Thereafter, the annual number of patients decreased slightly each year. 2) The mean age attreatmentwas 3 years and 7 months (44.5±12.9 months). 3) Concerning the regional distribution, more than 50% of the children came from Nagano Prefecture areas other than Shiojiri City, where our university is located. 4) With respect to feeding methods during infancy, most children were breast fed or mixed breast and bottle fed. Furthermore, any feeding irregularity was noted. 5) The mean interval from birth until the start of weaning was 7.5±4.1 months. The mean interval until completion of weaning was 16.0±6.3 months. 6) 95.5% of the children habitually brushed their teeth. The frequency of tooth brushing was "once a day" or "sometimes" in 69.5% of the children. 7) Overall, 46.9% of the children had received fluoride application

焼結ルチル二酸化チタン上の骨芽細胞様細胞の増殖およびアルカリホスファターゼ活性

The purpose of this study is creation of biomaterials from titanium dioxide (TiO2). This TiO2 has known for photocatalysis and osteogenesis. For the purpose of applying this function to orthodontic brackets and coating materials for implant, the relationship between surface of sintered and cell proliferation were examined. In addition, crystal structure and the surface property of sintering TiO2 were investigated. TiO2 were sintered at 1300°C for use as samples. We examined surface roughness, x-ray diffraction and scanning electron microscopy to make observations of the surface properties and texture. Moreover, mouse osteoblast-like cell line, MC3T3-E1 was cultured on sintered TiO2 in order to evaluate the cell proliferation and ALP. For the samples sintered at 1300°C, the crystalline phase of rutile-type TiO2 was confirmed.5000-fold magnified SEMimages of the surface of the unsintered samples, needle-like TiO2 crystals were pressure welded and showed mutual overlap, with pores occurring among the crystals. Sintering at 1300°C produced numerous small pores. Rutile TiO2 as a starting material was sintered at 1300°C and subjected to a cell culture experiment in which MC3T3-E1 cells were cultured on the sample, followed by viable cell counting and cell morphology observationon days 7, 14, 21, and 28 of culture. In the test of cell proliferation, sintered at 1300°C samples was found to remarkable cell proliferation even after time had passed. ALP activity of cells on 1300°C TiO2 sample, the values were 110% and 126% on days 14 and 28 of culture, respectively. These changes were calculated using polystyrene dish as the reference condition. Thus, TiO2 sintered at 1300°C showed good compatibility and increase in the ALP activity in MC3T3-E1 cells

Histochemical Characteristics of Tertiary Dentin Due to Calcium Hydroxide Paste in Rats

Calcium hydroxide is mainly used for dental pulp capping and it is thought that it induces hard tissue formation far better than other materials. Experimentally verifying this fact, Nishikawa et al revealed that bone-like dentin corresponding to tertiary dentin is rapidly formed when calcium hydroxide is applied directly to the pulp. Utilizing the same experimental system, histochemical study of the newly formed hard tissue (reparative dentin) was carried out and the results thereof were reported. Thick and irregular reparative dentin was formed in the pulp cavity and partial narrowing of the root canal was observed in m-CT. Histopathologically, the irregular reparative dentin increased its thickness obliterating the root canal having a diff erent Azan staining of aniline blue compared to primary dentin. Numerous cellular inclusion bodies were also trapped inside the thick dentin. Furthermore, with Schmorl’s thionine picric acid staining,thick reparative dentin was noted around the pulp cavity and dentin. The dentin was densely stained with picric acid with diff erent staining ability from the surrounding dentin. In addition, it was clearly confi rmed that many cells were trapped in reparative dentin. The results of the experiment suggest that the characteristics of the newly formed reparative dentin is comparable to tertiary dentin