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Multipoint analysis of anatomical condylar movement using dental CT
Get PDFapplication/pdfThe aim of this study was to develop a method for integrating morphological coordinates obtained with dental computer tomography (CT) and jaw movement coordinates acquired with a mandibular movement measuring device in order to enable multipoint analysis of anatomical condylar movements to be performed. The study subjects were two volunteers. One of the subjects displayed mandibular deviation and had a deformed condyle (on the deviated side), while the other subject exhibited normal occlusion and had healthy condyles. We placed three lead markers in front of each of the subjectsʼ ears and used them to integrate dental CT–derived morphological volume data and jaw movement data, both of which were obtained while the subjects were in the same seated position. Regarding the reproducibility of the reference point data, the positioning and orientation data obtained with the condylar movement measurement system exhibited maximum standard deviation values of 0.162 mm and 0.0₇4°, respectively, while the equivalent data acquired with the CT coordinate system displayed maximum standard deviation values of 0.068 mm and 0.00₇°, respectively. This suggested that reference point errors had little effect on our multipoint analysis of anatomical condylar movement and that the method used to transform the CT coordinates was highly precise. These results indicate that our method for integrating dental CT–derived coordinates with those acquired using a condylar movement measuring device leads to minimal errors in the positional/rotational data for the reference markers and hence, facilitates multipoint analyses of anatomical condylar movement.journal articl
イットリア部分安定化ジルコニアの焼成温度と相変態
Get PDFapplication/pdfThe objective of this study was to verify the stability of Y2O3 partially stabilized zirconia (zirconia) sintered at 1,350℃ and 1,450℃ in a simulated oral environment over a long period of time. After sintering, zirconia was immersed in physiological saline, 1% lactic acid solution, and 1% malic acid solution which can be produced in the oral cavity for 3 or 6 months. The amount of yttrium released, and transformation from the tetragonal phase to monoclinic phase by X–ray diffraction were evaluated. Using X–ray diffraction, the monoclinic phase hardly existed for zirconia sintered at 1,350℃; however, for zirconia sintered at 1,450℃, the monoclinic phase existed. The amount of yttrium released was small after exposure to both 1% lactic acid solution and 1% malic acid solution for zirconia sintered at 1,350℃. In contrast, it showed a maximum relase after exposure for 6 months form zirconia sintered at 1,450℃. Based on the X–ray diffraction, the monoclinic phase did not increase for zirconia sintered at 1,350℃ after exposure to 1% lactic acid solution and 1% malic acid solution for 3 and 6 months. However, there was marked transformation for zirconia sintered at 1,450℃ after exposure for 6 months. The frequency of the monoclinic crystal structures increased with the release of yttrium, as confirmed by the results of X–ray diffraction and measurement. As a result of structural observation, the crystal grain size of zirconia sintered at 1,350℃ was finer than that sintered at 1,450℃. It was clarified that zirconia sintered at 1,350℃ was more suitable than that sintered at 1,450℃ as an implant material.journal articl
Retinal Angiomatous Proliferation in an Eye with Cuticular Drusen
Get PDFapplication/pdfPurpose: To report the presence of retinal angiomatous proliferation (RAP) in an eye with cuticular drusen detected by fluorescein and indocyanine green angiography by confocal scanning laser ophthalmoscopy and by spectral-domain optical coherence tomography (SD-OCT). Methods: Case report of a 65-year-old Japanese woman with cuticular drusen. Results: At her first ophthalmic examination, her visual acuity was 20/20 in both eyes. An ophthal-moscopy showed many small subretinal pigment epithelial deposits in both eyes. These de-posits had a ‘saw-tooth pattern’ in the SD-OCT images. During the follow-up examination, retinal hemorrhages were observed, and fluorescein angiography showed a ‘stars-in-the-sky’ appearance and intraretinal neovascularization. The patient was diagnosed with cuticular drusen associated with RAP. Conclusion: We suggest that the cuticular drusen were associ-ated with RAP, so periodic follow-up examinations are needed for patients with cuticular drusen for the early detection and treatment of RAP.journal articl
Proteome Analysis Identifies the Dpr Protein of Streptococcus mutans as an Important Factor in the Presence of Early Streptococcal Colonizers of Tooth Surfaces
Get PDFapplication/pdfOral streptococci are primary colonizers of tooth surfaces and Streptococcus mutans is the principal causative agent of dental caries in humans. A number of proteins are involved in the formation of monospecies biofilms by S. mutans. This study analyzed the protein expression profiles of S. mutans biofilms formed in the presence or absence of S. gordonii, a pioneer colonizer of the tooth surface, by two-dimensional gel electrophoresis (2-DE). After identifying S. mutans proteins by Mass spectrometric analysis, their expression in the presence of S. gordonii was analyzed. S. mutans was inoculated with or without S. gordonii DL1. The two species were compartmentalized using 0.2-μl Anopore membranes. The biofilms on polystyrene plates were harvested, and the solubilized proteins were separated by 2-DE. When S. mutans biofilms were formed in the presence of S. gordonii, the peroxide resistance protein Dpr of the former showed 4.3-fold increased expression compared to biofilms that developed in the absence of the pioneer colonizer. In addition, we performed a competition assay using S. mutans antioxidant protein mutants together with S. gordonii and other initial colonizers. Growth of the dpr-knockout S. mutans mutant was significantly inhibited by S. gordonii, as well as by S. sanguinis. Furthermore, a cell viability assay revealed that the viability of the dpr-defective mutant was significantly attenuated compared to the wild-type strain when co-cultured with S. gordonii. Therefore, these results suggest that Dpr might be one of the essential proteins for S. mutans survival on teeth in the presence of early colonizing oral streptococci.journal articl
Association of Self-reported Height Loss and Kyphosis with Loss of Teeth in Japanese Elderly
Get PDFapplication/pdfStudy background: Height loss and kyphosis are useful surrogate markers of osteoporotic vertebral fractures in the elderly. Loss of teeth in the elderly also is associated with osteoporosis. These imply the possibility that self-reported these indices may be associated with loss of teeth in the elderly. This study aimed to clarify the associations of self-reported height loss and kyphosis with number of teeth lost in Japanese elderly. Subjects and Methods: Among patients who visited dispensing pharmacies in Matsumoto, Japan, 307 patients (75 men and 232 women) aged 50–97 years participated in the study. They completed a structured questionnaire including covariates related to loss of teeth. Self-reported height loss and kyphosis were simply defined as three categories: no; mild-to-moderate; severe. Results: Analyses of covariance adjusted for covariates revealed that there were no significant differences in the numbers of teeth lost in total, or during the past 1 year among the three self-reported height loss categories. Significant differences were observed in the total numbers of teeth lost among the three self-reported kyphosis categories (p<0.001). Subjects who were conscious of severe kyphosis had significantly larger number of teeth lost (mean ± SEM, 16.1 ± 1.8) than those who were conscious of no kyphosis (8.7 ± 0.6, p<0.001) and mild-to-moderate kyphosis (8.3 ± 0.7, p<0.001). Furthermore, there were significant differences in the number of teeth lost during the past 1 year among the three self-reported kyphosis categories (p=0.031). Subjects who were conscious of severe kyphosis had significantly greater number of teeth lost during the past 1 year (0.9 ± 0.2) than those who were conscious of no kyphosis (0.3 ±0.1, p=0.03). Conclusions: Our results suggest that Japanese elderly with self-reported severe kyphosis may lost more teeth than those without self-reported severe kyphosis.journal articl
咬合高径を実験的に低下させた場合の咬合高径と咀嚼運動の変化
Get PDF松本歯科大学博士（歯学）2013甲第147号application/pdf[目的]歯科医療の現場では，咬合の回復，咬合の調整，咬合の誘導，新しい咬合の設定など咬合に関する治療が盛んに行われてきた．しかし，患者にとって不適切な咬合高径の設定は，口腔機能においてさまざまな障害をきたすことが知られている．適切な咬合高径の設定が咀嚼機能において重要であり，咬合高径を変化させた場合の生体反応を明らかにすることが必要とされている．しかし，これらの障害の起因となる病態生理学的メカニズムはいまだ不明である．これまでの研究で，咬合高径挙上モデル動物の実験では，増加した咬合高径は数日で生来の咬合高径となるように調節されることが報告されている．また，咀嚼中の顎運動を分析すると，リズムに変化は認められないが，開口量が減少し，最大開口位が変化しないことが認められている．これらのことから，咀嚼運動パターンの中枢プログラムは生来の咬合高径と強い関係があることが示唆されている．しかし，咬合高径の低下が同様の結果となるかは不明である．また，咬合高径の低下法には，歯を削合する方法もあるが，歯の削合は咬合関係の不適や削合による疼痛を引き起こしている可能性があり，咬合高径低下以外の要因が含まれる．そこで本研究では，常生歯をもつモルモットに顎間ゴムを装着した咬合高径低下モデル動物を作製すること，および顎間ゴム撤去後の咬合高径と咀嚼中の顎運動の経日的変化を調べることを目的とした．[方法]実験にはHartley系雄性モルモットを用いた．矯正用ワイヤーで製作した可徹式のフックを頭蓋骨と下顎骨に装着した．これらのフックに顎間ゴムを装着して咬合高径低下モデル動物を作製した．顎間ゴムは10日間装着し，咬合高径の計測には，小動物用三次元エックス線マイクロCT撮影装置を用いて，断層像により，左右のオトガイ孔を正中矢状断像に投影した点と，切歯孔とを結んだ線を咬合高径として計測した．咀嚼運動の記録は動物を脳定位固定装置に固定し，下顎に装着したLEDの前頭面における軌跡を，CCDカメラで追跡することにより行い，咀嚼時間，最小開口位，最大開口位，開口量を計測した．記録は，顎間ゴムを装着した-10日目，顎間ゴムを撤去した0，1，4，7，11，14，18，21，25日目に測定し，咬合高径の変化に伴う顎運動の変化を解析した．また，同様の術式で，顎間ゴムを装着しなかった動物を対照群とし，実験群との比較，検討を行った．[結果および考察]咬合高径は10日間の顎間ゴム装着によって約５％低下し，対照群と有意差を示した．また，低下した咬合高径は，顎間ゴム撤去後25日目まで回復しなかった．咀嚼中の顎運動の比較では，顎間ゴム撤去後に咬合高径低下に伴い，最小開口位は減少したが，開口量に有意な増大が認められ，最大開口位は実験群と対照群では有意な差が認められなかった．また，咀嚼サイクルの時間に実験群と対照群で有意差は認められなかった．咬合高径低下群では，顎間ゴムの使用により咬合高径が低下することが明らかとなり，咬合高径低下モデル動物を作製することができた．咬合高径低下時の咀嚼中の顎運動は，最大開口位が変化しないように調節されており，この咬合高径低下の咀嚼運動プログラミングに対する影響は咬合挙上によるものと同様であることが示された．doctoral thesi
局所麻酔薬の組織血流量への影響−家兎背部への皮下注射による皮膚血流量の変化−
Get PDF松本歯科大学博士（歯学）2013甲第148号application/pdfWe examined the influence of lidocaine, mepivacaine, ropivacaine , bupivacaine , and levobupivacaine on skin blood flow in rabbits using a laser Doppler blood flowmeter. New Zealand White rabbits were anesthetized with sodium thiopental. 0.2 ml of 0.125～ 2.0% lidocaine, 0.125～3.0% mepivacaine, 0.125～0.75% ropivacaine, 0.125～0.5% bupivacaine, 0.125～0.75% levobupivacaine, 2.0% lidocaine with adrenaline (A) (1/80,000), and 3.0% propitocaine with felypressin (0.03 IU) were injected subcutaneously into the back skin of the rabbit’s. Physiological saline (0.2 ml) was injected as a control. We measured the skin blood flow using a laser Doppler blood flowmeter before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8, 9, and 10 minutes after the injection. The blood flow after the injection of each local anesthetic was converted into a percentage of the control value (before injection). The mean values of the skin blood flow before the injection in each group showed no significant differences. The skin blood flow was increased 30 seconds after the injection of physiological saline and showed no significant changes from 1 to 10 minutes after the injection. The skin blood flow was significantly increased by the subcutaneous injection of 0.125, 0.25, 0.5, 0.75, 1.0, and 2.0% lidocaine, 1.0, 2.0, and 3.0% mepivacaine, 0.125, 0.25, and 0.5% bupivacaine, and 0.75% levobupivacaine. The skin blood flow was significantly decreased by the injection of 0.125, 0.25, 0.5, and 0.75% mepivacaine, 0.125, 0.25, 0.5, and 0.75% ropivacaine, 0.125, 0.25, and 0.5% levobupivacaine. Lidocaine and bupivacaine increased the skin blood flow dependent on their concentration. On the other hand, ropivacaine decreased the skin blood flow dependent on its concentration. Mepivacaine decreased the skin blood flow at concentrations lower than 0.75% and increased it at a concentration higher than 1.0%. Levobupivacaine decreased the skin blood flow at concentrations lower than 0.5%, and increased it at those higher than 0.75%. The 0.5% bupivacaine and 2.0% lidocaine led to the most marked increase in skin blood flow, and 2.0% lidocaine?A and 0.75% ropivacaine led to the most marked decrease.doctoral thesi
Role of ECF sigma factors in biofilm formation ofPorphyromonas gingivalis
Get PDF松本歯科大学博士（歯学）2013甲第150号application/pdf【背景と目的】歯周病原細菌であるPorphyromonas gingivalis (以下P. gingivalis)は偏性嫌気性グラム陰性桿菌であり，歯周ポケット底部の嫌気度の高い部位にバイオフィルムを形成，感染し，病原性を発現する．しかし，口腔内は外界に開かれた環境で，温度，酸素，pH，栄養状態，他の細菌や宿主細胞など周囲環境からの影響を受けやすい．よって，P. gingivalisは，周囲環境ストレス対して何らかの回避機構を備えていることが予測される． そこで本研究では，周囲環境ストレスを回避するうえで重要なECF(extra cytoplasmic function)シグマ因子に注目し，P. gingivalisのECFシグマ因子と周囲環境ストレス回避機構としてのバイオフィルム形成との関連性について検討した．【材料と方法】用いた細菌株はP. gingivalis ATCC33277と，それを親株としたECFシグマ因子変異株，および相補株であった．まず5種類のECFシグマ因子遺伝子のクローニングを行い，その後ベクターに組み込み，親株に導入し，ECFシグマ因子変異株を得た．また，PGN_0274とPGN_1740については，両遺伝子とその周辺部をベクターに組み込み，各々の変異株に導入して相補株を得た．次に，デジタル比色計にて増殖速度を測定した．バイオフィルムの形成については，濁度を揃え，クリスタルバイオレット染色後，その吸光度を測定した．【結果】(1)親株と比較し，PGN_1740変異株が著明に増殖速度の低い値を示した．(2)野生株と比較し，PGN_0274変異株， PGN_0319変異株， PGN_1740変異株はバイオフィルム形成能の有意な増加を認めた．中でも，PGN_0274とPGN_1740変異株にて著明な増加を認めた．(3)PGN_0274とPGN_1740変異株におけるバイオフィルム形成量の増加は，それぞれの相補株にて野生株と同程度に回復した．【考察と結論】PGN_0274とPGN_1740は，P. gingivalisのバイオフィルム形成に関わるタンパク質の遺伝子発現を調節している可能性が示唆された．よって，これらのECFシグマ因子を標的とした抗菌薬を創薬することが実現すれば，選択毒性の高い優れた薬剤となることが示唆された．doctoral thesi
Association of cortical shape of the mandible on panoramic radiographs with mandibular trabecular bone structure in Japanese adults: a cone-beam CT-image analysis
Get PDF松本歯科大学博士（歯学）2013甲第158号application/pdfObjectives The purpose of this study was to assess the association between the cortical shape of the mandible, as detected on panoramic radiographs, and trabecular bone structure, as assessed by cone-beam computed tomography (CBCT), in Japanese adults. Methods Panoramic radiographs and CBCT images of the mandibles of 50 subjects (18 men, 32 women), aged 45–86 years, were evaluated. An experienced oral and maxillofacial radiologist categorized the cortical shape of the mandible as detected on panoramic radiographs as normal, mildly to moderately eroded, and severely eroded cortices, respectively. All mandibles were scanned using CBCT. Four bone structure parameters of the basal portion of the mandible were calculated in three dimensions using an image-analysis system: total bone volume (mm3); cortical bone volume fraction (%); trabecular bone volume fraction (%); fractal dimension. One-way analysis of covariance with Bonferroni correction was employed to evaluate differences in the four bone parameters among the three cortical shape groups. Pearson’s correlation coefficient was calculated to examine correlations between age and cortical and trabecular bone volume fractions.Results Progression of cortical bone erosion was significantly associated with increased trabecular bone volume fraction (P\0.001) and increased fractal dimension(P = 0.01). Cortical bone volume fraction decreased significantly with age (P = 0.04). However, trabecular bone volume fraction tended to increase with age (P = 0.06). Conclusions The change in the trabecular bone structure of the mandible may differ from that of the general skeleton in Japanese adults.thesi
