The organic and inorganic milieu of the oral cavity is regulated in large part through the secretions of salivary glands. These secretions are activated by a number of cellular signaling mechanisms, a major one being the cellular Ca²⁺ signaling system. Activation of phospholipase C by G-protein-coupled receptors results in release of intracellular Ca²⁺ and activation of Ca²⁺ channels in the plasma membrane. The intracellular release of Ca²⁺ is signaled by the second messenger, inositol 1,4,5-trisphosphate. Ca²⁺ entry involves signaling from depleted intracellular stores to plasma membrane Ca²⁺ channels, a process referred to as capacitative calcium entry or store-operated calcium entry. The electrophysiological current associated with capacitative calcium entry is the calcium-release-activated calcium current, or I_crac. In the twenty years since the inception of the concept of capacitative calcium entry, a variety of activation mechanisms have been proposed, and there has been considerable interest in the possibility of transient receptor potential channels functioning as store-operated channels. However, in the past two years, two major players in both the signaling and permeation mechanisms for store-operated channels have been discovered : Stim1 (and possibly Stim2) and the Orai proteins. Activation of store-operated channels involves an endoplasmic reticulum Ca²⁺ sensor called Stim1. Stim1 acts by redistributing within a small component of the endoplasmic reticulum, approaching the plasma membrane, but does not appear to translocate into the plasma membrane. Stim1, either directly or indirectly, signals to plasma membrane Orai proteins which constitute pore-forming subunits of store-operated channels.

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A number of studies have attempted to elucidate the biostimulatory effects of bone formation by low-level laser irradiation (LLLI) ; however, the molecular basis of the mechanism remains obscure. The administration of IGF-II/IGFBP-2 prevents the loss of bone mineral density in osteoporosis and stimulated bone formation. In the present study, to elucidate the mechanism of LLLI on bone formation, osteoblast-like cells MC3T3-E1 established from mouse calvaria cells were irradiated with LLLI and the IGF-II and IGFBP-2 mRNA gene expression levels were analyzed. Reverse transcription-polymerase chain reaction (RT-PCR) demonstrated that IGF-II and IGFBP-2 mRNA levels were increased by LLLI. The quantitative analysis of increased mRNA level was also confirmed by real-time PCR. These findings suggest that the increased IGF-II and IGFBP-2 gene expressions by LLLI in osteoblastic cells may be involved in the stimulation of bone formation.

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The purposes of the present study were to investigate the difference in craniofacial size of M. fascicularis (crab-eating monkey) living in wild and captive environments and to analyze the allometry between craniofacial size and body weight. Total of 111 M. fascicularis female skulls, included 82 wild, and 29 captive or bred in artificial environment in Japan Monkey Centre were examined. Thirty two cranial landmarks, body weight, humeral length and femoral length were measured using a digital caliper. Also, cranial index, difference of the measurement (D) and ratio of the difference to wild (R) were used. Allometric analysis was performed among those measurements in two groups. It could be seen that all measured dimensions were larger in the captive group than the wild. These differences in craniofacial size seemed to be related to the high level of nutrition. The measurements (D) and (R) of the facial region tended to be higher than those of neurocranial region and limbs. Slopes of all measurements were low against ideal values, isometric baseline or references. These implied that increase in body weight in captive environments were excessive against the other measurements.

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Pleomorphic adenoma, which is the major histopathological type of salivary gland tumor, shows polymorphous features including proliferating epithelial components with tubulo-ducatal and/or solid nests and mesenchyme-like components with myxomatous, myxo-chondromatous, and/or fibrohyalinized tissues. The process of metaplasia, which involves progressive changes in tissues, results in the transformation of fully differentiated cells of one type into differentiated cells of another type in various organs and diseases. Therefore, metaplastic change is an important morphological factor that determines the individual characteristics and typical histogenesis of various lesions. The purpose of the present study was to investigate metaplastic changes histopathologically and immunohistochemically using antibodies against high-molecular-weight keratin (34βE12), mitochondrial protein (MIT) and gross cystic disease fluid protein-15 (BRST-2) in order to clarify the morphological nature and mechanism of the metaplastic change in pleomorphic adenomas. These antibodies are known to be useful markers of squamous, oncocytic and apocrine-like metaplasia, respectively. Histopathologically, the parenchyma of pleomorphic adenoma consisted of double-layered epithelial elements showing luminal and abluminal arrangements, continuously adjacent to mesenchyme-like elements with myxomatous, myxochondromatous and/or hyalinized tissues. The epithelial parenchyma contained squamous eddies with polygonal cells and/or horny keratin pearls (10/10 cases), eosinophilic cuboidal and/or columnar oncocytic cells (8/10 cases), and also apocrine-like features (3/10 cases). Immunohistochemically, 34βE12-positive cells corresponded to the squamous eddies, whereas MIT- and BRST-2-positive cells corresponded to the eosinophilic, oncocytic cells and apocrine-like cells, respectively. In addition, positive immunoreactivity for 34βE12, MIT and BRST-2 was evident at luminal sites, and 34βE12 was expressed at abluminal sites in this tumor. These results suggest that metaplasia of squamous epithelium is associated with both ductal or luminal differentiation and abluminal differentiation of basal and myoepithelial cells, whereas, metaplastic changes of oncocytes and apocrine cells are related to ductal, luminal proliferation, comprising the typical polymorphous features of pleomorphic adenoma.

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New bone formation around implants has been evaluated two-dimensionally by the histopathological examination of sections. However, micro-computed tomography (micro-CT) allows the three-dimensional observation of bone structure. The purpose of this study is to compare bone mineral density and area of newly formed bone around implants with two types of surface treatment. We evaluated the influence of differences in surface treatment using micro-CT. The Ti-6Al-4V alloy implants (3.1 mm in diameter and 30.0 mm in length) underwent mechanical polishing (‘machined”) as a control or shot-blast surface treatment (‘blasted’) and their average surface roughness was≤0.70. The implants were inserted into the femurs of New Zealand White rabbits (16 weeks old). After 4, 8, 12, 24, and 48 weeks, pull-out tests were performed and the rabbit femurs were studied after the tests. The bone mineral density of newly formed bone was slightly higher for the blasted implants than for the machined implants from 4 to 48 weeks. Blasted implants showed a significantly greater area of newly formed bone around them after each observation period than did machined implants. These results suggested that surface treatment of implants is a factor affecting the bone mineral density and bone area. These micro-CT measurement results revealed that blasted surface was a factor for increasing the bone mineral density and bone area with time, in contrast to machined surface. Furthermore, micro-CT is a valuable analytical tool for assessing the implant-bone interface and the effect of implant surfaces on the quality and structure of newly formed bone.

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Purpose : This study aimed to comprehensively evaluate mastication in individuals wearing dentures with permanent resilient liners. Materials and Methods : Of the 53 patients who were randomly allocated into two groups, 26 and 27 patients received mandibular complete dentures with an acrylic resilient liner (ARL) and conventional acrylic resin (CAR), respectively ; 24 patients who had previously received mandibular complete dentures with a silicone resilient liner (SRL) served as a historical control. Mandibular movement during mastication was analyzed in 12, 10, and 10 age- and gender-matched subjects selected from the SRL, ARL, and CAR groups. Dynamic viscoelasticity and Shore A hardness tests were carried out to verify the relationship between the clinical trial findings and the mechanical properties of SRL, ARL, and CAR. Results : The masticatory performance of the SRL group was significantly higher than that of the ARL and CAR groups. Compared to the CAR and ARL groups, the SRL group showed longer occluding time in the initial, middle, and final phases. There were no significant differences in the maximum bite force among the three groups. The tanδ value of ARL was higher than those of SRL and CAR. The shear storage modulus G' and shear loss modulus G'' of CAR were higher than those of ARL and SRL. The hardness value of ARL was significantly greater than that of SRL. Conclusion : The prolonged occluding time due to the softness of resilient denture materials may improve the masticatory performance of complete denture wearers.

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We studied the prevalence of manidipine-induced gingival overgrowth. The incidence of such overgrowth was 1%, and was found in only one case among the surveyed patients. Together with a review of the literature regarding the pathogenesis and clinical management of drug-induced gingival overgrowth, we describe a case of manidipine-induced gingival overgrowth.

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The objective of this study is to evaluate internal consistency of a pilot questionnaire derived from qualitative analysis based on Triandis theoretical framework and to highlight valuable items leading to design a final questionnaire that discriminate patient who intend to wear denture and those who do not. Materials and Methods : The cross-sectional survey was carried out with 43 edentulous patients who fulfilled the inclusion criteria and gave consent for participation. Pilot questionnaire was administered to the subjects and response was recorded for analysis. Items were analyzed by correlation matrix and internal consistency were assessed by Cronbach's alpha of four Triandis theoretical framework subscales ; intention, social factor, affect and perceived consequence. Results : Of 72 pilot questionnaire items, 11 items were discarded based on the analysis resulting 61 (10 intention, eight social factor, nine affect and 34 perceived consequence) remained as valuable items with respective value of Cronbach's alpha ranging from 0.75 to 0.91. Conclusion : A pilot questionnaire was developed as a preparatory step leading to design an advanced questionnaire in multi-center investigation. Further multi-center investigation is needed in the future to analyze construct and convergent validity of the questionnaire to measure patients' intention to accept the dentures.

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Distomolar (also known as the fourth molar) is an abnormality in the number of teeth. This finding is usually present on one side of the maxilla, and is comparatively rare as a bilateral finding. We encountered a case of bilateral maxillary distomolars on pantomography. The image reading reports of pantomography and cone-beam CT were created using the reporting system of our radiology department. As we observed panoramic computed radiography, we identified bilateral impacted third molars in the maxilla, with distomolars adjacent to each. Supernumerary teeth displayed normal tooth morphology with regard to crowns and roots but were slightly smaller than the third molars. On cone-beam CT, distomolars were found behind the third molar on both right and left sides of the maxilla. Distomolars were completely impacted, and parts of the roots were near the maxillary sinus on 3D cone-beam CT images.

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