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There is a growing need for a mouthguard sheet material with higher shock absorption and dispersion capacity than those obtained by conventional materials. A five-layer mouthguard sheet material was previously developed using laminated ethylene vinyl acetate and polyolefin copolymer resin. In this study, the shock absorption capacity and dispersion capability of the new sheet material were investigated and compared with those of other materials. Impact testing for the new sheet material showed that the force required to displace the sheet by 1 mm was significantly higher at all thicknesses (p<0.001), whereas the puncture energy and displacement were significantly lower than those for ethylene vinyl acetate (p<0.05). The five-layer mouthguard sheet material successfully absorbed and resisted shock. Therefore, the sheet material potentially increases resistance to applied deformation in teeth and alveolar bone and maintains structure. The five-layer sheet material could expand the range of mouthguard products and help prevent oral trauma. [ABSTRACT FROM AUTHOR]

Regular monitoring to keep a thletes' teeth and gums healthy is crucial to their com petitive success. The authors have provided dental check-ups and treatm ent counseling for a wide variety of athletes to date. We were recently given the opportunity to perform dental check-ups for five top men's tennis players in Japan. Since one person had com plained of daytime sleepiness, we were also asked to examine the group's sleep health. One athlete had a decayed tooth that required treatment; no other abnormal findings were identified for any of the players. Their periodontal tissue was generally in good health, except for some tartar deposits for two athletes. Home sleep tests (HSTs) diagnosed three of the athletes with mild obstructive sleep apnea (OSA), including the player whose chief com plaint was daytime sleepiness (respiratory disturbance index [RDI]: 11.9, minimum oxygen saturation [minS p02]: 89%). Since he expressed a desire to be treated during subsequent counseling, we fabricated and fitted him with a mandibular advancement device (MAD). Wearing the M AD im proved his sleep-quality indicators to within normal ranges (RDI: 4.3, m inSp02: 95%). Additionally, this player owned a dental night guard, custom - made by a local doctor to treat his sleep bruxism. To determine whether and how it affected his OSA, we conducted another overnight HST, this time with him wearing the night guard, and found his breathing quality to be even worse than when he had no dental appliance in place (RDI: 12.3, minS p02: 86%). One study has already found that night guards designed solely to tre at sleep bruxism can actually worsen breathing quality in people with OSA, crowding the oral cavity and impeding air exchange. Sports dentists could help athletes receive better health care and im prove their perform ance by ensuring their dental support activities are inform ed by know ledge about OSA, and reconsidering prescribing a night guard. [ABSTRACT FROM AUTHOR]

In this article, the author evaluates the condition of dental education system, particularly sports dentistry in Brazil, and also discusses about dental implant treatment and dental education curriculum in universities.

Objective The aim of this investigation was to review and evaluate oral health status and dental education in Brazil. [ABSTRACT FROM AUTHOR]

Purpose: For the effective functioning of a mouthguard (MG), thickness is an important factor, in addition to the fitness and wearer comfort. In the current preparation of various MGs, in which ethylene-vinyl acetate (EVA) or polyolefin (Ole) sheets are used, the shock absorption capacity is enhanced by increasing the thickness. However, discomfort increases with thickness; as a result, breathing and speaking may be affected. In addition, sufficient attention should be given to provide occlusal harmony. In this study, we have carried out a basic investigation concerning the shock absorption in order to apply commercially available urethane gels to MGs. Methods: As MG materials, 2 mm and 3 mm sheets of EVA and Ole were used. In addition, commercially available 1 mm and 2 mm Hyper Gels (HGs) were used as a shock-absorbing material; that is, HG15 and HG30 having different degrees of hardness were used. The test specimen was placed on the instrument stage, a steel ball of 5 g was allowed to fall freely from a height of 500 mm to impact the specimen, and the shock acceleration at the time of impact was measured. For statistical analysis, one-way analysis of variance and Tukey's multiple comparison test were used. Result: When 2-mm HG15 or 2-mm HG30 was inserted between 2-mm sheets of EVA, the shock acceleration was significantly lower (p<0.05) and the shock-absorbing effect was higher with HG15 than with HG30. On the other hand, a significant difference was not observed between HG15 and HG 30 in the case of Ole. The shock acceleration was significantly lower (p<0.01) for the specimen in which 1-mm HG15 was inserted between 2-mm Ole sheets (5 mm in total) than for the laminate comprising two 3-mm Ole sheets (6 mm in total). Conclusion: The present results suggest that Hyper Gel, which has a high shock absorption capacity, but is inexpensive and easy to handle, can be applied to custom-made MGs. [ABSTRACT FROM AUTHOR]

Mouthguards (MG) are used mainly to prevent and reduce sporting injuries, but are also used in resistance training. We measured the greatest and total work loads during trunk extension/flexion exercise with and without MG using a multi-purpose muscle function evaluation system in 9 healthy dentulous subjects. Simultaneously, the electromyographic activity patterns and maximum voluntary activities of the temporal, masseter, and digastric muscles were measured. From obtained muscle activities, the relative percentage (%) of the activity of each masticatory muscle to its maximum voluntary activity was calculated, and masticatory muscle activities during trunk extension/flexion exercise were compared between with and without the use of MG. Based on physical performance and electromyographic masticatory muscle activity patterns during exertion of trunk muscles, no improvement in physical performance was observed using MG. However, the use of MG was useful for reducing the activities of the masticatory muscles, particularly the digastric muscle. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of wearing a custom-made mouthguard (CMG) on the dynamic state of the stomatognathic system and Center of Gravity (COG) sway in athletes with cerebral palsy (CP). Method: In four athletes (mean age 25.4 years) from the CP soccer club team AS United, the COG sway was measured before and after wearing the CMG. We performed simultaneous electromyogram (EMG) recordings of temporal muscles, masseter muscles and digastric muscles. The CMGs were fabricated from 2-mm single-layer-type MG21 (CGK) using the conventional method. A stabilometry system was used to measure COG sway. Measurements were repeated three times, 60 s each time, at 100 Hz. We determined the to ta l locus length and outlined area. EMG measurements were taken using a multi-telemeter system (WEB-5000, Nihon Kohden, Tokyo, Japan). The jaw in intercuspal position with minimum occlusal force was set as the baseline position. No specific instructions were given for jaw position during the measurement. Mean effective values were calculated from measured data, and relative ratios were calculated with maximum amount of muscle activity being 100%. Results: Analysis of COG sway indicated significant improvement in total locus length and total area on wearing a CMG. In addition, activity of the temporal muscles decreased and activity of the masseter and digastric muscles increased in athletes with CP after wearing a CMG, suggesting a tendency to clench their jaws. Although activity of the digastric muscles increased, as no significant mouth opening was seen during the experiment, this was likely used to stabilize the mandible. In an age-matched healthy control group, no changes were seen in COG sway and in activity of the masticatory muscles with the use of the CMG. Conclusion: We focused on CMG as a factor affecting COG sway in athletes with CP and compared the COG sway and masticatory muscle activity with and without use of a CMG. According to COG measurements, both total length and total area decreased in participants wearing a CMG. The amount of muscle activity decreased in the temporal muscles and increased in the masseter and digastric muscles during COG measurement in athletes with CP. [ABSTRACT FROM AUTHOR]

In 1973, rotaviruses A (RVAs) were discovered as major causative agents of acute gastroenteritis in infants and young children worldwide. The infectious RV virion is an icosahedral particle composed of three concentric protein layers surrounding the 11 double-stranded (dsRNA) segments. An in vitro replication system for RVs in permanent cell lines was developed in 1982 and expanded to replication in intestinal organoids in 2015. However, the details of rotavirus (RV) entry into cells and particle maturation mechanisms at the molecular level remain incompletely understood. Slowing down human RVA replication in cell culture on ice allowed morphological visualization of virus particle entry and the assembly of triplelayered particles (virion). Although RVAs are non-enveloped viruses, after virus attachment to the cell membrane, the virus enters the cell by perforating the plasma membrane by a fusion mechanism involving VP5* of the cleaved VP4 protein, as the alternative virus entry route besides the receptor-mediated endocytosis which is generally accepted. After assembling double-layered particles (DLPs) in viroplasm or cytoplasm, they appear to be connected with the endoplasmic reticulum (ER) membrane and become coated with outer capsid proteins (VP4 and VP7) in a coating process. The perforation of the ER membrane is caused by an unknown mechanism following interaction between non-structural protein 4 (NSP4) and the inner capsid protein VP6 of the DLPs. The coating process is closely related to the formation of a hetero-oligomeric complex (NSP4, VP4 and VP7). These lines of evidence suggest the existence of novel mechanisms of RV morphogenesis. [ABSTRACT FROM AUTHOR]

This paper presents the correlation between the difference of the dispersion state of particles such as LiCoO2 and acetylene black in the slurries and the electrochemical behavior. Three different preparation processes were applied to achieve the different dispersion state of particles in slurries, and thus obtained slurries are characterized by rheological measurement. It is found that dispersion process with highly loaded slurry or under high shear flow reduces elastic moduli and that their combination achieved the most dispersed state of the particles among the slurries investigated. X-ray computed tomography unveiled that the electrodes manufactured from these slurries contain the aggregates and the size of aggregates in the electrodes was reduced with the decrease in elastic moduli of slurry. At the discharge current density of 10 mA g-1, these electrodes exhibited 140 mAh g-1 of discharge capacities. At 1000 mA g-1, the electrode prepared from highly loaded slurry maintained 80% of the capacity that obtained at the current density of 10 mA g-1. The capacity of the electrode prepared from the slurry under highly loaded and high shear flow, on the other hand, dropped below 10%, indicated that the electrode from the most dispersed slurry has the worst rate performance. [ABSTRACT FROM AUTHOR]

Considering the scarce information on occurrences of Toxoplasma gondii and Neospora caninum in domestic animals from Turkey, the aim of this study was to investigate the seroprevalence of these parasite infections in cattle, horses, sheep, goats and dogs in Turkey. The specific antibodies against T. gondii and N. caninum were detected by iELISAs based on the recombinant TgSAG2 or NcSAG1 in a total of 2,039 serum samples from eleven provinces. The seroprevalence of T. gondii infections was 46.3%, 4.0%, 20.0%, 12.9% and 19.8%, that of N. caninum infections was 0.3%, 7.4%, 2.1%, 3.2% and 16.6% in the horses, cattle, sheep, goats and dogs, respectively. These results indicated that T. gondii and N. caninum infections are prevalent in Turkish domestic animals. [ABSTRACT FROM AUTHOR]

We were asked by the local organizing committee to provide first--aid to injured players at the 19th World Karate Championship. In this paper, we describe the arrangements made at the Centre and the frequency of injuries. The 19th World Karatedo Championship was held for 4 days starting November 13, 2008 at the Nihon Budokan. During this event, we recorded the number of injured players who visited the first--aid station, the site of injury, and treatment rendered. There were four courts in the Nihon Budokan, and a rescue table was placed at the side of each court. A Japanese doctor, dentist, nurse and translator were stationed and emergency treatment for brain concussion and nose-bleed during the matches was provided. An emergency corner was prepared midway as a first--aid station and foreign medical staff also provided emergency treatment with us. Serious cases which needed sutures or other minor surgical procedures were taken to the emergency room. A total of 199 players and/or staff visited the first--aid station during the 4 days of the tournament. The majority of the injuries were nosebleeds, followed by face and lip lacerations. Most of the cases received ice packs on the bruise and nasal packs to stop the nasal bleeding as treatment. Four players who were seriously injured were taken to hospital by ambulance. The emergency treatment was initiated by the dentist in cooperation with the doctor at the first--aid station. Extraoral injuries are very common in Karatedo, and so doctors request the assistance of dentists. There are many cases in which a dentist plays an active role in providing emergency treatment, indicating that more sports dentists need to be trained. [ABSTRACT FROM AUTHOR]

Babesia gibsoni is a tick-borne apicomplexan parasite of dogs that often causes fever and hemolytic anemia with highly variable clinical outcome. In this study, we sequenced the 254bp Internal Transcribed Spacer 1 region (ITS1) of 54 B. gibsoni isolates from 14 different geographical regions of Japan. The 54 isolates shared high sequence identity with each other and with B. gibsoni isolates reported in GenBank database (97.2-100%). Consistent with previous reports, phylogenetic analysis showed that B. gibsoni isolates from Japan formed the same clade with those from U.S.A., Australia, India and Taiwan. Our finding indicates that B. gibsoni ITS1 region is highly conserved among isolates from dogs in Japan, making it a useful genetic marker for molecular epidemiology of the parasite. [ABSTRACT FROM AUTHOR]

In 73 gDNA samples from Babesia gibsoni-infected dogs, the M121I variant population was measured by using allele-specific real-time PCR. Although the mechanism of atovaquone against B. gibsoni has not been clearly identified, it is reported that the mitochondria cytochrome b gene of the atovaquone-resistant B. gibsoni had a single-nucleotide substitution at nt363 (G to T), which resulted in the substitution of methionine with isoleucine (M121I). In this study, 3/73 samples showed over 5% M121I variant population. Although the M121I variant population is a low percentage, it runs the risk of spreading drug-resistant parasites. It is important to prevent the spread of drug-resistance, so we need to gather information about this at regular intervals. [ABSTRACT FROM AUTHOR]

In this working group, occlusion of mouthguards in relation to different sport activities and occlusal adjustments were discussed. [ABSTRACT FROM AUTHOR]

A fabrication process via the double-emulsion method is proposed for silica hard-shell microcapsules (HSMCs) that contain trimethylolethane (TME) hydrate. The TME-encapsulating silica-HSMCs are promising materials for reusable phase-change materials for latent-heat transportation systems. The obtained silica-HSMCs were visualized by a scanning electron microscope. The amount of TME hydrate inside the capsules was confirmed using a differential scanning calorimeter. The measured latent heat of the TME-encapsulating silica-HSMC was a reasonable fit to the predicted value. [ABSTRACT FROM AUTHOR]