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Get PDFThe objectives of this empirical study were to evaluate the quantitative and qualitative alterations experienced by community-dwelling elderly and their families when employing oral home telecare (a care service system based on interactive motion-picture transmission between households and healthcare providers). The subjects were four community-dwelling elderly in Kuriyama-cho, Hokkaido. The tutorial programs were designed to provide health information and education, as well as to enhance life skills related to exercise and communication. The programs were provided to the elderly through a new oral healthcare interactive learning system disseminated via an ISDNbased network. Quantitative and qualitative observation data on oral home telecare were collected by videophone and subsequently discussed. Functional independence in daily activities, communication skills, and social cognition, independence in oral care, and oral hygiene status all improved. Clients and their families were able to acquire broader knowledge relating to oral and general health, practical oral homecare skills, and social life skills. The use of this home telecare system as a "preventive home visit" and as a "living environmental tool" incorporating broad social supports could help improve the quality of life of clients and become part of a community oral healthcare service.departmental bulletin pape
Get PDFPurpose: Electrical potential may facilitate the moving of corroded metal ions across radicular dentin to cause allergic reaction. This study was to investigate the effect of electrical potentials on the penetration of silver and copper ions through radicular dentin. Materials and Methods: Eighty-eight dentin discs were prepared from intact premolar teeth and placed between two containers of the model. One container was filled with copper and/or silver solution. Another container was filled with 0.9% sodium chloride solution. Five levels of electrical potential were applied to the model at 37°C for 1 and 24 hrs. Then silver and copper ions in sodium chloride solution were measured by ICP-ES. The data was analyzed by one-way ANOVA with Tukey comparison test and student's t-test (P<0.05). Results: The concentrations of metal ions significantly increased as the electrical potentials increased when above 250 mV were applied after 1 hr. The concentrations of silver ions were significantly greater than those of copper ions. Low concentrations of silver and copper ions were detected after 24 hrs at 125 mV level. Conclusions: These results suggest that the penetration of corroded silver and copper ions through radicular dentin caused by intraoral potential might be minimal.departmental bulletin pape
Get PDFHypophosphatasia (HOPS) is a heritable disorder characterized by defective skeletal mineralization, deficiency of tissue-nonspecific alkaline phosphatase (TNSALP) activity and premature loss of deciduous teeth. In a previous study, we detected missense mutations in the TNSALP gene of a patient who inherited the F310L and the V365I mutation with severe periodontitis and childhood HOPS. Expression of the mutant V365I TNSALP gene using COS-1 cells demonstrated that the protein translated from the mutant had undetectable ALP activity. In the present study, we characterized another ALP enzyme translated from the mutant F310L and compared it with the ALP in the patient's serum. The COS-1 cells transfected with the F310L and co-transfected with F310L and V365I (F310L/V365I) exhibited levels of 67% and 31%, respectively, with the enzymatic activity of the wild-type taken as 100%. In the thermostability test, TNSALPs in the COS-1 cells transfected with the mutant F310L or F310L/V365I were significantly more heat labile compared with that of the wild-type. Moreover, ALP from the patient's serum was also more heat labile than normal ALP. These results suggest that the protein translated from the mutant F310L, in addition to the mutant V365I, may be responsible for the expression of symptoms of the childhood-type HOPS.departmental bulletin pape
Get PDFThe purpose of the present study was to measure tongue pressure with the aim of characterizing the pattern of linguopalatal contact during articulating glossal sounds in normal subjects and glossectomy patients. Tongue pressures against the palate were evaluated in 13 normal subjects and 5 glossectomy patients by using three parameters: the duration from the onset of linguopalatal contact to the time of maximum pressure, the maximum pressure, and anterior posterior ratio of the maximum pressure. Three glossal sounds, [ti], [tʃi], and [ʃi], which have tendency of mishearing in glossectomy patients, were selected for test sounds. A unique characteristic was demonstrated in normal subjects. The score of the maximum pressure showed an apparent order among the three sounds, while the durations revealed the opposite order. Anterior posterior ratio of the maximum pressure also showed some relationship among three sounds. In glossectomy patients, these characters were not found. The loss of tongue volume or deterioration of tongue mobility causes these results.departmental bulletin pape
Get PDFRunx2/Cbfa1 is essential for osteoblast differentiation and bone formation. Runx2 null mice (Runx2-/-) completely lack mineralized tissue and die soon after birth, whereas Runx2 heterozygous knock-out mice (Runx2+/-) stay alive but show morphological defects in the skeletal system as observed in cleidocranial dysplasia (CCD) in humans. The aim of this study is to elucidate the role of Runx2 in adult mineralized tissue and also to reveal the distinct features of heterozygous deletion of Runx2 in response to tooth movement. Therefore, we examined the cranium, tooth and the periodontium in adult Runx2+/- using soft X-ray and micro-CT. In addition, tooth movement induced by mechanical loading was evaluated. In adult Runx2+/-, crown: root ratio of the first maxillary molar was significantly lower than that of wild type (WT). Irregularities in root morphology was also observed. The cranium was narrow with thin parietal bone compared to WT. Mechanical stressinduced tooth movement was similar between Runx2+/- and WT in terms of movement distance. However, while rotational movement between the first and third week was increased in WT, it was not altered in Runx2+/- mice. These data indicate that Runx2 plays a role in cranium and the tooth development in adulthood.departmental bulletin pape
Get PDFReduction of the size of food platform of a distal extension removable partial denture has been recommended to decrease functional load on the abutment teeth and residual ridges. The purpose of this study was to investigate the influence of shortening food platform on masticatory performance. Eight subjects unilaterally missing mandibular molars participated in the study. A unilateral design was used for the denture framework. The length of the food platform was changed as follows. Initially, (A) was adjusted so that the distal end of the platform was in accordance with the distal end of maxillary second molar. Next, the platform was shortened successively to 15 mm (B) and 10 mm (C). Subjects were asked to masticate 2-colored wax cubes to evaluate masticatory performance. Mixing Ability Index was calculated from the color mixture and the form of masticated cubes. Repeated measures one-way ANOVA indicated significant difference of Mixing Ability Index among platforms (P＜0.0001). The Dunnett's test indicated no significant difference between A (1.27±0.29) and B (1.36±0.29), and a significant difference between A and C (0.89±0.30), (P＜0.001). Masticatory performance decreased significantly when the length of food platform was shortened to 10 mm.departmental bulletin pape
Get PDFThe purpose of this study was to investigate a suitable occlusal height for an implant prosthesis by examining the responses of the periodontal tissues around a natural antagonist. The subjects were three Japanese females with two posterior missing teeth restored by ITI system implants (Straumann). Two kinds of experimental implant prostheses were adjusted as follows; one was adjusted in heavy clenching (HC), and the other was adjusted in light clenching (LC). The periodontal pulsation, displacement during biting an occlusal force meter and the mobility of the antagonist were measured before and one week after temporary cementing HC and LC, and one week after removal. In each prosthesis, there was no significant difference in the amounts of the pulsation and mobility of the antagonist before and one week after cementing, and one week after removal (p>0.05). The displacement of the antagonist during biting the occlusal force meter did not change much during the conditions. The results of this study suggested that an implant prosthesis adjusted not only under heavy clenching but light clenching like crown restorations for natural teeth did not affect the periodontal tissues of the antagonist in a harmful manner.departmental bulletin pape
Get PDFTo study long-term degradation of polycarbonate (PC) and the formation and the release of bisphenol A (BPA) in vivo and in vitro, PC brackets placed in the oral cavity for 18-40 months as well as bracket, denture plate, and temporary crown placed in water at 37°C for 34 months were examined for the changes of BPA content and molecular weight in PC using high performance liquid chromatography and size exclusion chromatography. BPA release in vitro was also monitored. The BPA content and molecular weight for the brackets in vivo showed a tendency to increase from 38-60 μg/g to 324- 697 μg/g and to decrease from 49 x 103-54 x 103 to 43 x 103-45 x 103 during 18-40 months, respectively. The content and total release of BPA in vitro after 34 months were 472 and 37.4 μg/g for bracket, 130 and 2.2 μg/g for denture plate, and 50 and 2.8 μg/g for temporary crown, respectively. BPA appeared to be released more in saliva than that expected from the in vitro data. Additives contained in the PC materials were suggested to influence the formation of BPA.departmental bulletin pape
Get PDFMitral annular calcification (MAC) is a commoncondition in elderly subjects that sometimescauses degenerative mitral valvular diseases. Toinvestigate the early histopathogenesis of MAC, weexamined 180 consecutive autopsies of elderlysubjects. After a macroscopic and radiologicalexamination, 5-mm-thick serial tissue blocksobtained from the mitral annulus were examined inall MAC cases. Five cases without MAC were alsostudied using histology, immunostaining, electronmicroscopy, analytical electron microscopy andthe TUNEL method. The incidence of MAC infemales (23%) was higher than that in males(15%). Most MAC was located at the posteriorcusp (91%). The mitral annulus showed signs ofmicroscopic calcification and lipid-deposition insome degenerated areas in all of the cases withoutMAC. The interstitial cells were positive forvimentin and partially positive for smooth muscleactin, indicating the myofibroblastic differentiation.Ultrastructural studies showed an abundanceof cellular degradation products and foci ofcalcium- and phosphorus-deposition on theseproducts in the interstitium. Several interstitialcells tested positive for both single-stranded DNAimmunostaining and the TUNEL reaction. In conclusion,the microscopic calcification of mitralannulus is an early stage of MAC and caused bycalcium-deposition on cellular degradation products,probably released from apoptotic or necroticinterstitial cells.departmental bulletin pape
Get PDFMechanisms of disc displacement in temporomandibular joint (TMJ) internal derangement (ID) in mandibular asymmetry have not been clearly defined. This study examines the degree and direction of disc displacement and their relationship with vertical asymmetry in terms of both clinical and biomechanical aspects. A retrospective study of disc displacement was performed in 31 mandibular asymmetry patients using MR imaging. The degree and direction of disc displacements on the shifted side and contralateral side TMJ were investigated with the degree of vertical asymmetry. Furthermore, three-dimensional finite element models of entire mandible include TMJ and maxillary teeth in occlusion were created to simulate displacement of the articular disc during clenching condition. The direction of displacement on the shifted side and contralateral side were significantly different. Articular disc has tendencies to displace more on the shifted side even in mild degree of vertical asymmetry. The degree of displacement was correlated with the amount of asymmetry. The MR results were consistent with the tendencies of disc displacement predicted from the finite element models. We suggest that disturbance in the direction of stress distribution through asymmetry of the mandible is one of the mechanisms related to disc displacement.departmental bulletin pape