Based on arthroscopic findings in patients with temporomandibular joint arthrosis, the present study divided the synovial membrane in the upper joint cavity into anterior and posterior sections in relation to the articular disc. The relationship between temporomandibular arthralgia and site of synovitis was investigated. Temporomandibular arthralgia was assessed using the Visual Analog Scale, and severity of arthralgia during resting, mouth opening, protrusive movement, lateral movement, clenching and occlusion was quantified. Results:A correlation was observed between synovitis and temporomandibular arthralgia (p<0.01). Synovitis occurred most often in the posterior section, followed by the posterior region of the anterior section, and anterior section, respectively. Anterior synovitis correlated to pain during mouth opening, protrusive movement, lateral movement of the affected side, and lateral movement of the normal side. Posterior synovitis was associated with pain during mouth opening, protrusive movement, lateral movement of the affected side and occlusion. Degree of arthralgia during mouth opening associated with posterior synovitis was significantly worse than that associated with anterior synovitis (p<0.05). However, the degree of correlation between synovitis and pain at rest and during clenching was low.

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We have previously reported that chick serum (CKS) strongly induced adipogenesis in Meckel's chondrocyte in vitro, but little is known about the effects on other mesenchymal cells. In the present study, CKS-induced adipogenesis on the osteogenic MC3T3-E1 cells, mouse subcutaneous fibroblasts (MSF), and undifferentiated mouse dental pulp cells (MDP) were examined using light and electron microscopy, immunofluorescence staining, and BrdU-incorporation for DNA-synthesizing cells. Furthermore, MSF was cultured on a collagen-gel matrix that allowed maintenance of three-dimensional integrity. CKS facilitated lipogenesis and induced the formation of lipid droplets in all kinds of cells. Immunostaining showed the expression of peroxisome proliferator-activated receptor-γ in immature adipocytes, and leptin and glucose transporter-4 in mature adipocytes. Adipocytes on collagen-gel matrix induced unilocular lipid droplets at a high frequency. These morphological observations strongly indicate that these lipid-rich cells retain sufficient features as intact adipocytes, although the adipocytes that were formed in the present study were multilocular adipocytes. Furthermore, it was suggested that CKS agents involved in adipocyte differentiation are a common inductive factor affecting various mesenchymal cells.

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An objective methodology of color reproduction based on color science has been attempted for dental restoration. The purpose of this study was to evaluate the accuracy in reproducing a tooth color gradation in ceramic by means of a Computer Color Matching (CCM) system employing a prototype program and spectrophotometer measurements. The colors of 5 shade tabs of VITAPAN 3D MASTER were measured for 4 regions of each tooth from the incisal to the gingival area. Ceramic prescriptions calculated by CCM program were used to fabricate tooth shaped ceramic specimens using IPS Empress 2. Formulated ceramic powders were applied to the color regions and blended at the interfaces for shade continuity. Color coordinates L^*, a^* and b^* of ceramic specimens and target shade tabs for each pair in 10 incremental areas (each 1 mm x 3 mm) indicated very similar values. Color difference (dE) were below 3.6 in all 10 incremental areas. It was concluded that the CCM methodology reproduced the target tooth color gradation at a clinically satisfactory level.

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Porphyromonas endodontalis, a gram-negative anaerobic rod, is an important pathogenic organism in periapical lesions with acute symptoms, such as pain, swelling, and suppuration in endodontic patient. Like P. gingivalis, a major pathogen of adult periodontitis, P. endodontalis is asaccharolytic and forms black-pigmented colonies on enriched blood agar plates. However, pathogenic factors and pathological potential of this microbe have been poorly characterized. In this study, we assessed the adhesive abilities of P. endodontalis to gingival epithelial cell, and investigated whether P. endodontalis has a major fimbrial component of fimbrilin similar to that of P. gingivalis. Furthermore, the proteolytic activities of P. endodontalis were examined. The results indicated that P. endodontalis significantly adhered to a mouse gingival epithelial cell line, GE1, although the adhesive ability was lower than that of P. gingivalis. The electron microscopic investigations showed scarcely any fimbriae in P. endodontalis. Furthermore, PCR and the DNA-DNA hybridization analysis for the gene encoding fimbrilin (fimA) of P. gingivalis revealed that P. endodontalis did not have fimA or fimA-related genes, which could account for the lesser adhesive ability of P. endodontalis to gingival epithelial cells. The hydrolyzing profile toward various synthetic peptides showed that the spectrum of proteolytic activities of P. endodontalis was markedly different from that of P. gingivalis. Thus, the present findings indicate that P. endodontalis has a different adhesion mechanism from P. gingivalis fimbriae, and has a different spectrum of proteolytic activities from that of P. gingivalis, which may lead to the specific pathological potential of the organisms in periapical lesions in humans.

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We reported that phosphoryl-oligosaccharides (POs) prepared from potato starch hydrolysates strongly solubilize calcium and inhibit formation of calcium phosphate precipitates. The aim of this study was to examine the effects of POs on remineralization of caries-like lesions in enamel in vitro. Bovine enamel slabs were demineralized in a 0.1 M lactic acid gel (pH 5) at 37℃ for 3 w, and subsequently remineralized in a mineral solution (20 mM Hepes, 1.5 mM CaCl_2, 0.9 mM KH_2PO_4, pH 7 ) with addition of 2 ppm F^- as NaF or various concentrations of POs (0.07-4%) at 37℃ for 7 d. The mineral distributions in enamel were quantified by transversal microradiography. The mineral loss values (ΔZ, vol%・μm) in the samples treated by the mineral solution containing 0.07-0.2% POs were significantly lower (p<0.001) compared with demineralized enamel samples and were statistically similar to that in the samples in 2 ppm F group. Remineralization rates of the samples in the POs groups were inversely correlated with the logarithmic values of POs concentration with a significant correlation coefficient (r=0.99, p<0.0001). The present results suggested that POs may be a novel and unique substance to enhance enamel remineralization, and could be utilized for caries prevention by nutritional approach.

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It was previously shown that phosphoryl-oligosaccharide calcium (POs-Ca) can be prepared from potato starch hydrolysates and substantially promote the solubility of calcium. The aim of this study was to investigate the effects of a sugar-free chewing gum containing POs-Ca on remineralization of enamel and dentin in situ. Twelve healthy volunteers (6 males and 6 females ; mean age=22 y old) participated in a double-blind cross-over design intraoral study. Each participant wore a removable palatal appliance containing both of demineralized enamel and dentin disks and chewed a xylitol gum or xylitol plus 2.6% POs-Ca gum 4 times a day (period : 2 w per gum). The mineral distributions of the specimens were quantified by microradiography. The lesion depth (ld) of enamel (Mean±SD=70±11 μm) and dentin (71±13 μm) in the POs-Ca group were significantly reduced by 25-31% compared with the xylitol gum (101±21 μm in enamel and 95±13 μm in dentin ; p<0.001). The proposed mechanism of mineral accumulation by POs-Ca is that they contribute to increase salivary Ca/P ratio and maintain a state of supersaturation of calcium with respect to tooth substances enhancing remineralization. In conclusion, it was suggested that daily use of a sugar-free chewing gum containing 2.6% POs-Ca enhances remineralization both in enamel and dentin lesions considerably.

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Using photodensitometry for 47 patients who had congenitally missing permanent teeth, excluding for third molars, bone mineral content (BMC), determined via dental radiographs, was compared with a control group of 43 patients who have all their teeth. In addition, bone age was determined by hand-wrist radiographs using the TW 2 method, and the differences of skeletal maturation between both groups were evaluated. The results are as follows : 1. The average BMC was significantly lower in the group missing teeth than in the control group both for young males (aged 7-15 years old) and young females (aged 6-15 years old). 2. The BMC in the group of people missing more than three teeth was significantly lower than those in the groups of people missing one or two teeth. 3. Regarding the average BMC by the location of missing teeth : The maxillo-mandibular group had the lowest BMC, followed by the second lowest mandible group and finally the maxillary group. By type of missing teeth : The molar, which contained at least one molar and anterior-premolar teeth group, had the lowest BMC. Second lowest was the group missing premolar followed by the group missing anterior. 4. In the groups with missing teeth, bone age was lower by 0.97 years in young males compared to 1.18 years in young females. These results show delayed skeletal maturation. In conclusion, this study clearly indicates that compared to the control group BMC is lower, and skeletal maturity has a tendency to be delayed in children with missing teeth. These results can assist planning of orthodontic treatment to patients with congenitally missing teeth.

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The purpose of this study was to clarify the effects and mechanisms of lidocaine (1.0×10^-3M)on changes in contraction of the smooth muscle induced by voltage dependent Ca²⁺ channel (VDCC) stimulator, KCl(90mM), and receptor activated Ca²⁺ channel (RACC) agonist, adrenaline(2×10^-5M), in porcine lingual arteries.
The isometric tension and intracellular Ca²⁺ concentration ( [Ca²⁺]i) by the fura-2 microfluorometric methods were measured simultaneously, and from them we tried to deduce the depressing mechanism of lidocaine (1.0×10^-3M) on the contraction.
The results were obtained as follows:
(1) Lidocaine depressed the increase of contraction and [Ca²⁺]i induced by KCl and adrenaline in a concentration-dependent manner.
(2) Lidocaine depressed the increase of contraction and [Ca²⁺]i induced by adrenaline in normal physiological salt solution after depletion of the intracellular Ca²⁺-sensitive Ca²⁺ store.
(3) Lidocaine depressed the increase of contraction and [Ca²⁺]i induced by adrenaline in Ca²⁺-free physiological salt solution.
(4) Lidocaine had no effect on Ca²⁺ induced Ca²⁺ release(CICR) by caffein. These results suggest the following conclusions as follows,
1. Lidocaine depresses influx of Ca^{2+ t}hrough VDCC and RACC. 2. Lidocaine inhibits the increase of [Ca²⁺]i through IP₃ processes. 3. Lidocaine has no effect on CICR.

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The color of natural teeth is semi-translucent enamel with a high transparency and chromatic dentin. The purpose of this study is to analyze the optical properties of human dentin and the relationship between the color spectrum and metal elements in the dentin. 120 specimens of human dentin sample with a thickness of 0.5 mm (±0.05 mm) were made. Reflectance values were measured by a spectrophotometer CAS-ID 1 with a white backing and a black backing. Scattering coefficients, absorption coefficients, R-infinity, CIELAB color coordinates L*, a*, b* and Color depth SQ were calculated based on each reflectance value. Metal elements in dentin were analyzed by electron probe X-ray microanalyzer (EPMA) and Fe, Zn, Mg, Cu and Ni in 10 areas of each dentin specimen were quantified and averaged. Mean L* value of dentin was 11.6±4.7, 29.6±27.3 for SQ, 70.1±11.3 for a*, 11.6±4.3 for C* and -0.1±2.1 for b*. Ni indicated a positive correlation with a* and b* value, Zn showed a positive correlation with L* value. On the other hand, Mg indicated a negative correlation with a* value. It was concluded that those three metal elements could create the dentin color defined in this study.

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Regarding improved range of mouth opening for patients with temporoman-dibular joint arthrosis, improvements in elasticity of the upper joint cavity and relaxation of the articular capsule are believed to be involved. When the maxillary joint cavity is pressurized and irrigated, it expands, thus increasing volume. In the present study, to investigate the relationship between range of mouth opening and elasticity of the joint cavity in temporo-mandibular joint arthrosis, elasticity of the temporomandibular joint cavity was assessed mechanically based on volume of the upper joint cavity and changes in outflow before and after temporoman-dibular joint cavity irrigation. In addition, the relationship between these mechanical parameters and changes in range of mouth opening before and after irrigation was investigated. While outflow increased after irrigation in some patients with temporomandibular joint arthrosis (I type), it decreased after irrigation in others (D type). Of the 60 joints studied, 43 Type I joints (71.7%) were identified. Sufficient improvements in range of mouth opening could not be achieved when the elasticity and volume of the upper joint cavity were small and when relaxation of the upper joint cavity was seen after PLS.

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We have shown that conditioning stimulation of the amygdaloid nucleus has an inhibitory effect on the nociceptive responses of the somatosensory cortex. The purpose of this study is to investigate whether amygdaloid conditioning stimulation exerts influence on the nociceptive neurons in the medullary dorsal horn in the rat. The animals were anesthetized with N_2O-O_2 (2 : 1) and 0.5%-halothane, and immobilized with pancuronium bromide. The peripheral test stimulus (a single rectangular pulse of 2.0 msec in duration) was applied to the receptive field of nociceptive neurons, and the ipsilateral amygdaloid conditioning stimulation were trains of 33 pulses (0.5 msec in duration, 300 μA) delivered at 330Hz. Fifty-five WDR neurons were distributed in the superficial layers of the caudal nucleus and diffusely throughout the reticular subnucleus, whereas most of NS neurons (13/17) were distributed in the dorsal part of reticular subnucleus. The conditioning stimulation in the central nucleus, basomedial nucleus and basolateral nucleus, markedly inhibited the activities in 24 of 43 nociceptive neurons. The inhibitory effect was 45.3±16.1% (n=24) at maximum. The conditioning stimulation had almost no effect on the discharges of non-nociceptive neurons. In contrast, the conditioning stimulation in the lateral amygdaloid nucleus had no effect on the nociceptive and non-nociceptive neurons. The present results suggest that amygdaloid nucleus inhibits the ascending nociceptive information at the second order neurons. This amygdaloid antinociceptive effect may provide one of the neurophysiological bases for the stress-induced analgesia (SIA) observed in the presence of stress and fear.

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The functional role of CD14 as well as Toll-like receptors (TLRs) in the Porphyromonas gingivalis (P. gingivalis) LPS-induced activation of B cells was assessed, using CD14-, TLR2- and/or TLR4-overexpressed murine B cells (CH12.LX). After stimulation with P. gingivalis LPS, both CD14- and TLR4-transfected (but not TLR2-transfected) CH12.LX cells showed higher induction of NF-κB activation than a parent vector-transfected cells, suggesting that P. gingivalis LPS could induce B cell activation in a CD14-dependent pathway through TLR4 and NF-κB activation. Furthermore, the control CH12.LX cells proliferated under stimulation with P. gingivalis LPS, accompanied by up-regulations of transforming growth factor (TGF)-β and intereleukin (IL)-6 mRNA. In contrast, the overexpression of CD14 resulted in enhancement of the up-regulations of TGF-β mRNA, but not IL-6 mRNA or proliferative responses to P. gingivalis LPS. These results suggest that P. gingivalis LPS could induce B cell activation both in CD14-dependent and independent pathways. In a CD14-dependent pathway, TGF-β production could be induced upon stimulation with P. gingivalis LPS through TLR4 and NF-κB activation. A CD14-independent pathway could also exist in the P. gingivalis LPS-induced activation of B cells that leads to proliferation and IL-6 production.

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Positron emission tomography using fluorine-18 fluoro-deoxyglucose (FDG PET) is useful for the detection of malignant tumor recurrences and for the evaluation of a therapeutic response to these;including ones found in the lung, colon, head and neck regions. The experimental study demonstrated FDG uptake was higher in faster-growing rather than in slower-growing tumors. These findings show FDG accumulation exhibits cell cycle dependency. However, the precise mechanism remains to be elucidated. In this study, the relationship between FDG uptake and the cell cycle phase in HeLa S3 cells, as well as how they compare to the conventional tracer ⁶⁷Ga citrate (Ga) with single photon emission tomography (SPECT) was assessed. Synchronization of HeLa S3 cells was accomplished via a double thymidine block. The uptake of FDG and Ga was determined after cell cycle synchronization. The glucose transporter was independently evaluated for the level of its Glut 1 glucose transporter membrane protein. FDG uptake in HeLa S3 cells was significantly higher in the early S phase and G₂/M phase compared to the G₁ phase. In addition, Ga uptake was higher in the G₂/M phase. Immunochemical assays for the Glut 1 transporter showed an increase in membrane expression within S phase cells. It has been concluded that cell cycle dependency is reflected in the uptake of FDG and Ga, seen during PET or SPECT imaging of tumor tissue. These results reveal tumor proliferative activity, and can assist in evaluating a therapeutic response. Furthermore, the increased FDG uptake, in part due to increased membrane expression of the Glut 1 glucose transporter, contributes to this phenomenon.

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Minor salivary gland tumors were clinicopathologically evaluated. Between 1990 and 2000, 31 patients with minor salivary gland tumors (10 males and 21 females between 12 and 75 years of age, mean age : 49.9 years) were treated in our department. Minor salivary gland tumors most frequently occurred in the palate in 19 patients, followed by 5 in the buccal mucosa, 4 in the lips, and 1 in the oropharynx. Histopathological examinations revealed 20 benign and 11 malignant tumors. Pleomorphic adenoma accounted for the majority (19 cases) of the benign tumors. Malignant tumors consisted of 3 mucoepidermoid carcinomas, 3 adenoid cystic carcinomas, 1 adenocarcinoma, 1 acinic cell carcinoma, 1 salivary duct carcinoma, 1 tubular adenocarcinoma, and 1 basal cell adenocarcinoma. All cases of benign tumors were successfully treated by extirpation without tumor recurrence. Of the 11 cases of malignant tumors, 7 were treated by surgery alone, 1 was treated by surgery after chemotherapy, and 3 were treated by surgery after chemotherapy and radiotherapy. Primary lesions recurred in 2 of these patients. The outcomes of patients with malignant tumors were as follows : 6 patients survived without other complications, 3 died of uncontrollable tumors, and 2 died of other diseases. Of the 3 patients who died of uncontrollable tumors, 2 died of primary lesions and 1 died of cervical lymph node metastasis.

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