Evaluation of sleep bruxism by three-dimensional analysis of the deformation of acrylic resin occlusal appliances


Research presentations in yogyakarta, indonesia: academic conference report


Development of primary treatment for temporomandibular disorders: The Japanese Society for the Temporomandibular Joints evidence-based clinical practice guidelines, 2023 edition


顎口腔機能における感覚に関する研究手法

顎口腔機能における感覚に関する研究手法

The Journal of Japanese Society of Stomatognathic Function


Three-dimensional morphological changes in occlusal appliances under dry and wet conditions


顎運動検査の意義と今後の方向性

顎運動検査の意義と今後の方向性


Proposals and evaluations for the enhancement of CAD/CAM education


Efficacy of initial conservative treatment options for temporomandibular disorders: A network meta-analysis of randomized clinical trials

This network meta-analysis (NMA) of randomized controlled trials (RCTs) aimed to identify effective initial conservative treatment strategies for patients with temporomandibular joint disorders (TMD). RCTs comparing treatment options for TMD published between January 2000 and July 2021 were retrieved from the databases of PubMed and Embase via a comprehensive electronic search. Patients diagnosed with myalgia (muscle pain) or arthralgia (joint pain) according to pain-related Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were eligible for inclusion. Twelve treatment options and a placebo were included in the mutual comparisons. The risk of bias was assessed using Risk of Bias 2.0. Forest plots of direct comparisons between individual studies were created using MetaInsight. NMA was performed using R statistical software (netmeta). Twenty-four RCTs involving 1336 patients assessing pain and 12 RCTs involving 614 patients assessing maximal mouth opening were identified. Low-level laser therapy (standard mean difference [SMD]: -2.12, 95% confidence interval [CI]: -3.18, -1.06), self-exercise (SMD: -1.51, 95% CI: -2.82, -0.2), and stabilization splints (SMD: -1.16, 95% CI: -2.02, -0.29) were effective in improving pain; however, the certainty of evidence was very low. Self-exercise (SMD: 0.71, 95% CI: -0.58, 2.01), stabilization splints (SMD: 0.65, 95% CI: -0.09, 1.39), and low-level laser therapy (SMD: 0.63, 95% CI: -0.34, 1.6) were effective in improving maximal mouth opening; however, the certainty of evidence was very low. Stabilization splints, self-exercise, and low-level laser therapy may be effective in the initial treatment of TMD.


Bilateral transport of neuronal tracer after unilateral administration: Investigation of potential peripheral mechanism

Previous studies have shown pain attenuation after the administration of botulinum neurotoxin type A into the whisker pad contralateral to the nerve injury. It further showed localization in the neurons of the bilateral trigeminal ganglia, indicating a possible connection between the trigeminal nerves. Thus, this study aimed to investigate the potential link between the right and left trigeminal ganglia, considering their anatomical proximity and the possible neural interactions between these structures. The fluorogold (FG) neuronal tracer was localized in the neurons of both the right and left trigeminal ganglia (TG) after unilateral injection into the whisker pad. In contrast, there was a substantial decrease in FG localization in the contralateral ganglion following colchicine (CCh) administration or after midline incision surgery. Moreover, FG injected directly into the trigeminal ganglion was exclusively localized on the ipsilateral side. Additionally, systemic administration of FG revealed its localization not only within the bilateral TG neurons but also in the bilateral dorsal root ganglia (DRG) neurons, mirroring the findings following whisker pad injection. These findings suggest that bilateral transport of fluorogold occurs at the peripheral level, possibly through its diffusion from the injection site to the contralateral whisker pad and/or nerve axonal crossover through the midline. Further studies are required to clarify the specific peripheral pathways and explore the bilateral nerve connections.


Correlation between pierced earrings and metal allergy prevalence in Tokushima University hospital: A 15-year retrospective analysis

In Japan, metal allergies are becoming increasingly prevalent, raising concerns for public health. This study examined metal allergy characteristics, patient histories, and clinical signs associated with patch test results over a 15-year period at the Dental Metal Allergy Clinic of Tokushima University Hospital. A retrospective analysis of 1085 patients revealed that 65.4% tested positive for at least one metal allergen, with palladium chloride, nickel sulfate, potassium dichromate, and cobalt chloride identified as the most common allergens. Female patients were disproportionately affected, accounting for 78.4% of the study population. Notably, there was a substantial increase in patients reporting inflammation due to pierced earrings, increasing from 5.0% in 2005 to 43.2% in 2020, particularly among females. Patients with a history of inflammation from earrings had an 81.3% prevalence of metal allergies, which was significantly higher than the 60.4% reported in those without such a history (chi-square test, p < 0.001). These findings suggest a strong link between earrings and metal allergies, underscoring the need for improved education, early detection, and preventive strategies to address the growing impact of metal allergies on public health.


Association between physical function and edentulism in older adults: Findings from the indonesian family life survey 2014

This study aimed to determine the association between physical function and edentulism among older adults. The fifth wave of Indonesian Family Life Survey (IFLS-5) data was used. Physical function was evaluated through physical performance, physical capability, and appendicular skeletal muscle mass (ASM). Edentulous was found in 10.96% of 2554 older adults. Low physical performance (OR 2.02, 95% CI 1.32-3.09; = .001) was shown to be associated with edentulism in the 60 to 69 age group. In the 70 to 79 age group, both low physical performance (OR 1.62, 95% CI 1.04-2.53; = .033) and 1 dependency in ADL/IADL (OR 1.75, 95% CI 1.02-2.98; = .04) were significantly associated with edentulism. Two or more dependencies in ADL/IADL (OR 4.02, 95% CI 1.15-13.99; = .029) demonstrated significant association with edentulism in older adults 80 years. These findings highlighted the importance of maintaining natural teeth and improving oral health during the aging process.

Inquiry : a Journal of Medical Care Organization, Provision, and Financing


Effect of aromatherapy on sleep bruxism: A randomized double-blind crossover controlled tria

睡眠時ブラキシズムに対するアロマテラピーの効果 ―無作為化二重盲検クロスオーバー比較試験―


Associations between sleep bruxism, oral wetness, and salivary flow: A quantitative analysis


口腔顔面痛の対応およびトラニラストによる鎮痛効果

口腔顔面痛の対応およびトラニラストによる鎮痛効果

The Journal of the Japan Dental Association


Effect of soft denture liners on complete denture treatments: A systematic review

This systematic review examined the effectiveness of soft denture relining (SDR) materials. A comprehensive search of MEDLINE, Cochrane Library, and ICHUSHI was conducted up to July 26, 2020. Target outcomes were patient satisfaction, oral health-related quality of life (OHRQOL), masticatory ability (MA), denture functional duration, residual ridge resorption (RRR), and microbial contamination. An organization specializing in literature searches performed the reference searches, and two reviewers independently selected the literature sources, extracted the data, and assessed the risk of bias. The reviewers resolved any disagreements concerning the assortment of literature sources through discussion. SDR included acrylic- and silicone-based materials, which were evaluated separately. Reviewers selected 7, 5, 11, 1, 4, and 6 studies to assess patient satisfaction, OHRQOL, MA, functional duration, RRR, and microbial contamination, respectively. The results confirmed that SDR improved patient satisfaction, OHRQOL, MA, and RRR. However, the functional duration of SDR material is shorter than that of hard denture relining (HDR) or acrylic resin material. Furthermore, SDR material is more susceptible to microbial contamination in the long term. The risk of bias for the included studies tended to be high because of specific issues (difficulty in blinding SDR versus HDR). For patients who wear complete dentures, SDR often provides beneficial outcomes such as pain reduction and recovery from MA. However, caution should be exercised regarding their use owing to insufficient functional duration and the possibility of microbial contamination during long-term use.


Development of a novel chewing counter with a bone conduction sound system


A novel brief questionnaire using a face rating scale to assess dental anxiety and fear

This study aimed to evaluate the reliability and validity of a four-item questionnaire using a face rating scale to measure dental trait anxiety (DTA), dental trait fear (DTF), dental state anxiety (DSA), and dental state fear (DSF). Participants were consecutively selected from patients undergoing scaling (S-group; n = 47) and implant placement (I-group; n = 25). The S-group completed the questionnaire both before initial and second scaling, whereas the I-group responded on the pre-surgery day (Pre-day), the day of implant placement (Imp-day), and the day of suture removal (Post-day). The reliability in the S-group was evaluated using the test-retest method, showing a weighted kappa value of DTA, 0.61; DTF, 0.46; DSA, 0.67; DSF, 0.52. Criterion-related validity, assessed using the State-Trait Anxiety Inventory's trait anxiety and state anxiety, revealed positive correlations between trait anxiety and DTA/DTF (DTA, ϱ = 0.30; DTF, ϱ = 0.27, ϱ: correlation coefficient) and between state anxiety and all four items (DTA, ϱ = 0.41; DTF, ϱ = 0.32; DSA, ϱ = 0.25; DSF, ϱ = 0.25). Known-group validity was assessed using the initial data and Imp-day data from the S-group and I-group, respectively, revealing significantly higher DSA and DSF scores in the I-group than in the S-group. Responsiveness was gauged using I-group data, showing significantly lower DSA and DSF scores on post-day compared to other days. The newly developed questionnaire has acceptable reliability and validity for clinical use, suggesting its usefulness for research on dental anxiety and fear and for providing patient-specific dental care.


Effect of Carbonated Water Swallowing Volume on the Acoustic Characteristics of Swallowing Sounds in Healthy Adult Subjects

成人健常者における炭酸水嚥下量が嚥下音の音響特性に与える影響

Carbonated beverage-based sensory stimulation affects swallowing movements and contributes to safe swallowing. Although the effects of carbonated beverages on swallowing movements have been reported using swallowing sounds, small amounts of swallowing have not been investigated. In this study, we extracted the acoustic characteristics from swallowing sounds acquired when 15 healthy adults swallowed 3mL, 5mL, and 10mL of water or carbonated water five times each. Consequently, we confirmed that the acoustic features of the swallowing sound in time domain, i.e., peak intensity and energy, marginally significantly reduced when swallowing carbonated water compared to water, regardless of the quantity. Even with a mouthful volume of 3mL of carbonated water, this trend was confirmed. Therefore, the potential evaluation of swallowing and rehabilitation through the swallowing of small amounts of carbonated water, which has a lower risk of aspiration for dysphagia, was considered.

Transactions of the Japanese Society for Medical and Biological Engineering


Essence of diagnosis and management of sleep bruxism


This Report Details a Case of Allergic Contact Dermatitis Resulting From Exposure to Chromium in the Clasp of an Apple Watch Band


Risk of an immediate-type allergy to minocycline hydrochloride ointment

Operative Dentistry, Endodontology and Periodontology


Relationship between temporomandibular disorders and oral frailty/frailty in older people

超高齢者における顎関節症症状とオーラルフレイル・フレイルとの関連

Journal of the Japanese Society for the Temporomandibular Joint


Job shadowing for early undergraduate dental students: Validation of educational effectiveness using structural equation modeling

This study aimed to evaluate and validate the educational effectiveness of a job shadowing class as a dental teaching programme for preclinical dental students through a questionnaire that assessed related student perceptions. A total of 124 preclinical (second year) dental students at Tokushima University participated in job shadowing placements from 2017 to 2019. Each student observed dental practice or surgery for 1 day in the university hospital. After shadowing, the students were requested to fill out a nine-item questionnaire based on a five-point scale. The first analysis was performed to calculate the correlation for each item. Furthermore, regression analysis for the categorical data was performed to show the relationship between eight questions (Items 1-8) and one question (Item 9: comprehensive evaluation). Next, factor analysis was performed to determine students' perceptions regarding the shadowing class. Ninety-eight students (response rate: 79%) completed the questionnaire. There was a strong relationship amongst Items 1, 8 and 9 ("interested in dentistry as a job," "learning motivation" and "comprehensive evaluation" respectively) based on the results of the correlation and regression analysis. The factor analysis led to three student perceptions as latent factors, namely, "Interesting," "Self-awareness" and "Future Goal," which had a relatively close inter-factor correlation (0.465-0.772). The finding suggests that job shadowing may increase a students' interest in a dentistry career at an early stage of their education and learning motivation, along with generating self-awareness. This programme may present possible educational effectiveness in dental education.


Mechanism and clinical use of botulinum neurotoxin in head and facial region

Botulinum neurotoxin (BoNT) is a biological toxin produced by Clostridium botulinum. BoNT is a potent toxin extensively used in therapeutic interventions. This review provides an updated overview of the mechanisms of action and clinical applications of BoNT in head and facial region. MEDLINE/PubMed searches were conducted using the terms "botulinum neurotoxin" and "dentistry" along with a combination of other related terms. In addition, studies were manually selected from reference lists of the selected articles. The Food and Drug Administration in the United States initially approved BoNT to treat strabismus, blepharospasm, and hemifacial spasms. The use of BoNT in dermatology and cosmetics has been widely established and has created a revolution in these fields. Over the years, its applications in various medical specialties have expanded widely. Owing to its safety, efficacy, and long duration of action, it is well-accepted by patients. BoNT/A and BoNT/B are widely used in clinical practice. Several off-label uses of BoNT in the dental fraternity have yielded promising results. We have elaborated on the speculated mechanism of action, dosage, effective sites of injection, and adverse effects of each therapeutic application. The various clinical indications for BoNT include bruxism, myofascial pain, temporomandibular joint dislocation, hemifacial pain, orofacial dystonia, facial paralysis, chronic migraine, and trigeminal neuralgia. BoNT is a safe treatment that can be used effectively, provided that the clinician has adequate knowledge regarding the mechanism, injection techniques, and local and systemic side effects and that it is administered cautiously and purposefully.


First Step to Understand Jaw Movement -For the CAD/CAM Era-

顎運動を攻略するための第一歩 CAD/CAM 時代に向けて―

The Journal of Japanese Society of Stomatognathic Function


Targeted therapy for orofacial pain: A novel perspective for precision medicine

Orofacial pain (OFP) is a dental specialty that includes the diagnosis, management and treatment of disorders of the jaw, mouth, face, head and neck. Evidence-based understanding is critical in effectively treating OFPs as the pathophysiology of these conditions is multifactorial. Since OFP impacts the quality of life of the affected individuals, treating patients successfully is of the utmost significance. Despite the therapeutic choices available, treating OFP is still quite challenging, owing to inter-patient variations. The emerging trends in precision medicine could probably lead us to a paradigm shift in effectively managing the untreatable long-standing pain conditions. Precision medicine is designed based on the patient's genetic profile to meet their needs. Several significant relationships have been discovered based on the genetics and genomics of pain in the past, and some of the notable targets are discussed in this review. The scope of this review is to discuss preclinical and clinical trials that include approaches used in targeted therapy for orofacial pain. Future developments in pain medicine should benefit from current trends in research into novel therapeutic approaches.


Identification of microRNA signatures in peripheral blood of young women as potential biomarkers for metal allergy

MicroRNA (miRNA) is a short (19-24 nucleotide) endogenous non-protein RNA that exists in the body and controls the translation process from genes to proteins. It has become useful as a diagnostic tool and a potential treatment target in cancer research. To explore the function of miRNA in contact dermatitis, female participants with a positive metal allergy diagnosis ( = 3) were enrolled along with additional female participants with no medical history of metal allergy ( = 3). A patch test was performed on each participant. Peripheral blood was collected from all the participants before the patch test and at days 3 and 7 after starting the patch test. After total RNA was obtained from peripheral blood leukocytes and cDNA was generated, microarray analysis was performed to analyze the large-scale circulating miRNA profile. Real-time polymerase chain reaction (RT-PCR) was then used to clarify the overall target miRNA expression. Downregulation of hsa-let-7d-5p, hsa-miR-24-3p, hsa-miR-23b-3p, hsa-miR-26b-5p, and hsa-miR-150-5p was found on day 7. Certain miRNAs were confirmed using RT-PCR. These peripheral blood miRNAs could be diagnostic biomarkers for metal allergies.


Outline of Oral Psychosomatic Disorder and Prospects for New Concepts of the Oral Psychosomatic Disorder

歯科心身症の概要と新概念への展望


Survey of oral maxillofacial injury experiences and sports mouthguard use in wakeboarders

International Journal of Sports Dentistry


Relationship between oral parafunctional and postural habits and the symptoms of temporomandibular disorders: A survey-based cross-sectional cohort study using propensity score matching analysis

Temporomandibular disorders (TMDs) are a multifactorial joint disease of the masticatory system. The possible etiological factors involved in the onset and progression of TMDs include oral parafunctional habits (OPFHs) and postural habits (PHs). However, little information is available on the association between OPFHs and PHs and a predisposition to TMDs. Thus, to investigate whether the presence of OPFH and PH predisposes individuals to TMDs, a survey-based cross-sectional cohort study of self-reported TMD was performed. A total of 2292 patients with TMD were recruited for the survey. Through one-to-one propensity score matching, 166 patients with and without sleep bruxism (SB) were selected. The SB group had a significantly higher risk of masticatory muscular pain or fatigue than the non-SB group ( = 0.018). Furthermore, the SB group without other OFPHs and PHs did not show a significantly higher risk of TMD symptoms than the non-SB group. Diurnal clenching and bad posture also affect the stomatognathic system, causing pain or fatigue; however, it did not result in TMDs in patients without any OPFHs and PHs. This implies that OPFHs and PHs may increase the risk of TMD symptoms in coexistence with other habits.


Physical load while using a tablet at different tilt angles during sitting and standing

Few standards and guidelines to prevent health problems have been associated with tablet use. We estimated the effects of posture and tablet tilt angle on muscle activity and posture in healthy young adults. Seventeen healthy young adults (age: 20.5 ± 3 years) performed a cognitive task using a tablet in two posture (sitting and standing) and tablet tilt angle (0 degrees and 45 deg) conditions. Segment and joint kinematics were evaluated using 16 inertial measurement unit sensors. Neck, trunk, and upper limb electromyography (EMG) activities were monitored using 12 EMG sensors. Perceived discomfort, kinematics, and EMG activities were compared between conditions using the Friedman test. The perceived discomfort in the standing-0 deg condition was significantly higher than in the remaining three conditions. Standing posture and tablet inclination significantly reduced the sagittal segment and joint angles of the spine, compared with sitting and flat tablet conditions. Similarly, standing posture and tablet inclination significantly reduced EMG activities of the dorsal neck, upper, and lower trunk muscles, while increasing EMG activity of shoulder flexors. Standing posture and tablet inclination reduced the sagittal flexion angle, and dorsal neck, upper, and lower trunk muscle activities, while potentially increasing the muscle activity of arm flexors.


咬合違和感症候群の診療フローチャートの提案

咬合違和感症候群の診療フローチャートの提案

Journal of the Japanese Society for the Temporomandibular Joint


Therapy outcome measures in temporomandibular joint disorder: A scoping review

Therapy outcome measures (TOMs) in temporomandibular disorders (TMDs) have not been systematically evaluated. We systematically explored the main TOM assessment methods for TMD TOMs used in previous studies. Scoping review. According to Preferred Reporting Items for Systematic reviews and Meta-Analysis extension for Scoping Review reporting guidelines, we systematically searched five key databases (MEDLINE/PubMed, Web of Science, Embase, Epistemonikos and ClinicalTrials) and thoroughly scanned relevant grey literature using Medical Subject Headings, Emtree and index terms. We considered primary research papers published from January 2010 to December 2020 that included patients with TMD aged ≥18 years, diagnosed according to the Diagnostic Criteria for Temporomandibular Disorders. Four reviewers extracted general information and information on study design and setting, target, interventions, and outcome type. One hundred and seventy-two of the 3726 screened articles (3704 by search engines and 22 manually) were included. The TOMs analysed included pain (n=161 articles), maximal mouth opening (MMO) (91), jaw function (32), jaw movement (26), joint sound (16), quality of life (QOL) (15), depression/anxiety (14), oral QOL (10) or others (30). Evaluation periods were <4 weeks (111), <8 weeks (62), <12 weeks (59), >12 weeks (75) or 'not mentioned' (12). Pain outcomes (229) included general pain (115), tenderness (45), pain during functioning (44), resting pain (16) and others (8). Pain outcome evaluation methods included Visual Analogue Scale (VAS; 121), Numerical Rating Scale (21) and other methods (21). Pain outcome indicators were binary (10) or continuous (158); only five studies reported the least significant difference in treatment efficacy. MMO evaluation using painless methods (19) and jaw function evaluation using methods assessing mandibular movement range (23) were the most frequent. TMD TOMs are diverse; the major outcomes were pain, MMO, jaw function and jaw movement. Most pain outcomes are evaluated by VAS Score changes.


Dual orexin receptor antagonist drug suvorexant can help in amelioration of predictable chronic mild stress-induced hyperalgesia

This study aimed to evaluate the involvement of the orexin system in predictable chronic mild stress (PCMS) and the effects of suvorexant, a dual orexin receptor antagonist, on nociceptive behavior in PCMS. Male C57BL/6 J mice were separated into various PCMS groups: a control group with sawdust on the floor of the rearing cage (C), a group with mesh wire on the floor (M), and a group with water just below the mesh wire (W). Activation of lateral hypothalamic orexin neurons was assessed using immunofluorescence. In another experiment, half of the mice in each group were administered an intraperitoneal injection of suvorexant (10 mg/kg), and the remaining mice were injected with the same amount of vehicle (normal saline). Thermal hyperalgesia was examined using tail immersion and hot plate tests, while mechanical hyperalgesia was investigated using the tail pinch test after 21 days of PCMS. Animals subjected to PCMS showed an increased percentage of activated orexin neurons in the lateral hypothalamic region after 21 days. Mice raised in the PCMS environment showed increased pain sensitivity in several pain tests; however, the symptoms were significantly reduced by suvorexant administration. The findings revealed that PCMS activates hypothalamic orexin neuronal activity, and the use of suvorexant can help attenuate PCMS-induced thermal and mechanical hyperalgesia.


Analgesic effect of tranilast in an animal model of neuropathic pain and its role in the regulation of tetrahydrobiopterin synthesis

International Journal of Molecular Sciences


Orofacial pain: molecular mechanisms, diagnosis, and treatment 2021

The Special Issue ``Orofacial Pain: Molecular Mechanisms, Diagnosis, and Treatment 2021'' contains 6 articles published by 41 authors from different countries focusing on nucleus accumbens core GABAergic neurons, receptor-interacting serine/threonine-protein kinase 1, pannexin 1-mediated ATP signaling, ultra-low-frequency transcutaneous electrical nerve stimulation, and triamcinolone acetonide. The content covers several pain models, including neuropathic pain caused by peripheral nerve constriction or malpositioned dental implants, tongue cancer, myogenous temporomandibular dysfunction, and oral ulcerative mucositis. In addition, a review paper on trigeminal neuralgia is included.


Conditioned Medium From the Stem Cells of Human Exfoliated Deciduous Teeth Ameliorates Neuropathic Pain in a Partial Sciatic Nerve Ligation Model.

In neuropathic pain (NP), injury or diseases of the somatosensory system often result in highly debilitating chronic pain. Currently, there is no effective drug for the complete and definitive treatment of NP. We investigated the therapeutic potential of conditioned medium (CM) derived from stem cells from human exfoliated deciduous teeth (SHED-CM) against NP using a mouse partial sciatic nerve ligation (PSL) model. Abnormal pain sensation, such as tactile allodynia and hyperalgesia, can be caused by PSL. In the behavioral test, intravenous administration of SHED-CM greatly improved the PSL-induced hypersensitivity. We found that treatment with SHED-CM resulted in the recruitment of M2 macrophages in the injured sciatic nerve and ipsilateral L4/L5 dorsal root ganglion and suppressed microglial activation in the spinal cord. Notably, specific depletion of the anti-inflammatory M2 macrophages by mannosylated-Clodrosome markedly reduced the antinociceptive effect of SHED-CM. Intravenous administration of CM from M2 induced by SHED-CM (M2-CM) ameliorated the PSL-induced hypersensitivity. We found that M2-CM directly suppressed the expression of nociceptive receptors as well as proinflammatory mediators in Schwann cells. Taken together, our data suggest that SHED-CM ameliorates NP through the induction of the analgesic anti-inflammatory M2 macrophages. Thus, SHED-CM may be a novel therapeutic candidate for NP.


Burnout is associated with amount of work and sleep quality of public-school dentists in the Caraga region


Spatio-temporal differences in the Filipinos search trends for toothache and milk tea


Botulinum toxin injection attenuates nonodontogenic toothache: A case report


Peripherally Administered Botulinum Toxin Type A Localizes Bilaterally in Trigeminal Ganglia of Animal Model


Dentin-pulp complex tissue regeneration via three-dimensional cell sheet layering

The dentin-pulp complex is a unique structure in teeth that contains both hard and soft tissues. Generally, deep caries and trauma cause damage to the dentin-pulp complex, and if left untreated, this damage will progress to irreversible pulpitis. The aim of this study was to fabricate a layered cell sheet composed of rat dental pulp (DP) cells and odontogenic differentiation of pulp (OD) cells and to investigate the ability to regenerate the dentin-pulp complex in a scaffold tooth. We fabricated two single cell sheets composed of DP cells (DP cell sheet) or OD cells (OD cell sheet) and a layered cell sheet made by layering both cells. The characteristics of the fabricated cell sheets were analyzed using light microscopy, scanning electron microscope (SEM), hematoxylin-eosin (HE) staining, and immunohistochemistry (IHC). Furthermore, the cell sheets were transplanted into the subrenal capsule of immunocompromised mice for 8 weeks. After this, the regenerative capacity to form dentin-like tissue was evaluated using micro-computed tomography (micro-CT), HE staining, and IHC. The findings of SEM and IHC confirmed that layered cell sheets fabricated by stacking OD cells and DP cells maintained their cytological characteristics. Micro-CT of layered cell sheet transplants revealed a mineralized capping of the access cavity in the crown area, similar to that of natural dentin. In contrast, the OD cell sheet group demonstrated the formation of irregular fragments of mineralized tissue in the pulp cavity, and the DP cell sheet did not develop any hard tissue. Moreover, bone volume/tissue volume (BV/TV) showed a significant increase in hard tissue formation in the layered cell sheet group compared with that in the single cell sheet group ( < 0.05). HE staining also showed a combination of soft and hard tissue formation in the layered cell sheet group. Furthermore, IHC confirmed that the dentin-like tissue generated from the layered cell sheet expressed characteristic markers of dentin but not bone equivalent to that of a natural tooth. In conclusion, this study demonstrates the feasibility of regenerating dentin-pulp complex using a bioengineered tissue designed to simulate the anatomical structure. Impact statement The dentin-pulp complex can be destroyed by deep caries and trauma, which may cause pulpitis and progress to irreversible pulpitis, apical periodontitis, and even tooth loss. Current treatments cannot maintain pulp health, and teeth can become brittle. We developed a three-dimensional (3D) layered cell sheet using dental pulp cells and odontogenic differentiation of pulp cells for dentin-pulp complex regeneration. Our layered cell sheet enables the regeneration of an organized 3D dentin-pulp-like structure comparable with that of natural teeth. This layered cell sheet technology may contribute to dentin-pulp complex regeneration and provide a novel method for complex tissue engineering.


Low-intensity pulsed ultrasound ameliorates neuropathic pain induced by partial sciatic nerve ligation via regulating macrophage polarization


Longitudinal comparison between flipped classroom and team-based learning in a prosthodontic class

Active learning is a concept that allows students to study and learn actively by themselves to get knowledge. There are several methods of active learning, including flipped classroom (FC) and team-based learning (TBL). In FC, students are required to study before classes. In TBL, students also study before class, take individual readiness assurance test (iRAT) and team readiness assurance test (tRAT), then discuss group assignment projects (GAPs) during class. The purpose of this study was to compare the effectiveness between FC and TBL.
 The effectiveness of FC and TBL was assessed from the results of the term-end examinations, questionnaires and practice examinations. To check the difficulty of the term-end examinations, control dentists took the same examinations and we calculated the equating score with item response theory.
 Statistical analysis showed that the correct answer rate in term-end examinations was significantly different in comparison with the time of the trial, and for the participants (students and dentists). The term-end examination score of FC and TBL did not show a statistical difference. The student questionnaire showed that TBL had higher scores than FC on various factors such as student positive attitude, preparation, ingenuity of teacher and achieving the class goals. The crown & bridge score from the practice examination of 6th-year students who had FC + TBL were constantly higher than the Japanese national average score. The identification index of FC and TBL did not show the statistical difference and there was no statistical difference on item response theory between FC and TBL.


Decreased global interest in oral cancer during the COVID-19 pandemic

Oral cancer is one of the most common malignancies in developing countries, but studies using global data are scarce. The aim of this study is to analyze the search interests for oral cancer using mouth cancer, tongue cancer, gum cancer, and lip cancer as common keywords. Internet searches relating to oral cancer from 2010 to 2020, from 250 countries and dependent areas, were retrieved from Google Trends. Color densities in a heat map were used to show geographic differences. Kruskal-Wallis test with post hoc Dunn's analysis was used to perform yearly comparisons of searches for mouth cancer, tongue cancer, gum cancer, and lip cancer. Search results within 2020 were also compared to determine differences. Forecasting searches from 2021 to 2022 were done by fitting time series models. From 29 of 250 (11.6%) countries, the highest search values were observed for mouth cancer in Sri Lanka, Qatar, Bangladesh, Finland, Netherlands, Spain, and France. Compared to 2020, greater searches were seen in 2018 (Mdn = 91%, P = 0.023) and 2019 (Mdn = 94%, P = 0.012) for mouth cancer, and 2019 (Mdn = 17%, P = 0.035) for lip cancer. The relative search volumes for gum cancer and lip cancer were substantially lower than mouth cancer during the COVID-19 pandemic. Higher-income countries tend to be more interested in seeking information about oral cancer. Noteworthy decline in the interest in seeking information online for oral cancer may have crucial implications during the COVID-19 pandemic. Google Trends offer an invaluable and inexpensive means for oral cancer surveillance and health-seeking behavior. <br />.

Asian Pacific Journal of Cancer Prevention : APJCP


Risk factors for tooth loss in patients with 25 remaining teeth undergoing mid-long-term

International Journal of Environmental Research and Public Health


Pain sensitivity increases with sleep disturbance under predictable chronic mild stress in mice


Effects of sitting posture and jaw clenching on neck and trunk muscle activities during typing

Neck pain is one of the most common musculoskeletal complaints. Evidence suggests that increased activities of neck and trunk muscles are one of the mechanisms related to neck pain. Jaw clenching and sitting posture may modulate the muscle activity in neck and trunk muscles during typing. The present study aimed to assess the effects of different postural positions and clenching conditions on neck and trunk muscle activities. Thirteen healthy adults (39.8 ± 5.0 years) performed computer typing tasks in four conditions (two postural positions [upright vs slouched] and two jaw clenching conditions [clenching vs non-clenching]). Integrated surface electromyography (iEMG) was measured in sternocleidomastoid (SCM), upper trapezius (uTP) and middle trapezius (mTP) muscles and compared between conditions. The Friedman and Wilcoxon signed-rank tests with Bonferroni's corrections were used to estimate the condition-specific differences in the iEMG data. The statistical significance level was set at 5%. In both postural positions, iEMG was significantly greater under the jaw clenching than under the non-clenching condition (χ = 21.700, P < .01). Under both jaw clenching conditions, iEMG was significantly greater in the slouched than in the upright postural position (χ = 23.182, P < .01). No significant differences in iEMG were seen across conditions (χ = 5.018, P = .10). Sitting posture and jaw clenching appear to influence activities of different muscles.


インドネシアの歯学部における学部教育

インドネシアの歯学部における学部教育

The Journal of Japan Association of Oral Rehabilitation

日本口腔リハビリテーション学会雑誌


Immediate Effect of Masticatory Muscle Activity with Transcutaneous Electrical Nerve Stimulation in Muscle Pain of Temporomandibular Disorders Patients

Transcutaneous electrical nerve stimulation (TENS) is a non-invasive treatment modality for acute and chronic pain. However, little information for muscle activity is available on the immediate effects of TENS in masticatory muscle pain related to temporomandibular disorders (TMDs). The present study aimed to evaluate the immediate effects of TENS treatment on TMD-related muscle pain. Thirty-six patients with TMD-related muscle pain and 39 healthy subjects served as TMD and control groups, respectively. For objective evaluations, maximum mouth opening, and maximum bite force were measured before and after TENS. The pain intensity was assessed according to a 100-mm visual analog scale (VAS). TENS was applied to painful muscles for 20 min with frequencies of 100-200 Hz. The treatment outcome was evaluated using Global Rating of Change (GRC) scales. In the TMD group, VAS values significantly decreased after TENS. Although there was significant increase in the maximum mouth opening after TENS for only TMD group, the maximum bite force of both groups was significantly greater after TENS. According to GRC scales, one patient with TMD-related muscle pain expressed negative feelings after TENS. Conclusively, TENS treatment might quickly relieve pain in masticatory muscles and improve masticatory functions in patients with TMD-related muscle pain.


Evaluation of the measurement precision and accuracy in the dental CAD/CAM system

The purpose of this study is to investigate the precision and trueness of the occlusal contact record obtained with a dental CAD/CAM device (ARCTICA). Sandblasted spherical steel balls with diameters of 10-20 mm were measured using ARCTICA and a three-dimensional measurement device (FN503). The radius of each steel ball was calculated from the measured value and the difference between the measured and nominal values was obtained. Upper/lower dental arch casts were measured and processed for occlusal contact image creation using both devices. The graphical images of the occlusal contacts at the intercuspal position obtained from both systems and an occlusal analysis device (BE-1) were compared with the occlusal contact area. Excellent correlation was observed between the measurement results of ARCTICA and FN503 (p<0.001, R: 0.99). The occlusal contact areas were 186.0 mm (ARCTICA), 192.8 mm (FN503), and 196.1 mm (BE-1). This study showed that ARCTICA is capable of conducting highly accurate measurements and generating a graphical image of occlusal contacts with good reliability.


Forecasting interest in health professions education based on relative search volume trends from the Philippines


Risk factors for tooth loss in patients undergoing mid long-term maintenance: A retrospective study

In this retrospective study, we identified risk factors for tooth loss in patients undergoing mid-long-term maintenance therapy. We surveyed 674 maintenance patients for ≥5 years after active treatment who visited a dental clinic between January 2015 and December 2016. Of these, 265 were men (mean age 54.6 ± 8.0 years old) and 409 were women (mean age 54.0 ± 7.9 years old). Study variables included patient compliance, sex, number of teeth lost, cause of tooth loss (dental caries, periodontal disease, root fracture, others, vital or non-vital teeth), age at start of maintenance, number of remaining teeth at start of maintenance, smoking, use of salivary secretion inhibitors, presence of diabetes mellitus, condition of periodontal bone loss, and use of a removable denture. Most lost teeth were non-vital teeth (91.7% of all cases) and the most common cause of tooth loss was tooth fracture (62.1% of all cases). A statistically significant risk factors for tooth loss was number of remaining teeth at the start of maintenance ( = 0.003).


Role of CGRP in neuroimmune interaction via NFkB signalling genes in glial cells of trigeminal ganglia

Activation of the trigeminal system causes the release of various neuropeptides, cytokines, and other immune mediators. Calcitonin gene-related peptide (CGRP), which is a potent algogenic mediator, is expressed in the peripheral sensory neurons of trigeminal ganglion (TG). It affects the inflammatory responses and pain sensitivity by modulating the activity of glial cells. The primary aim of this study was to use array analysis to investigate the effect of CGRP on the glial cells of TG in regulating nuclear factor kappa B (NF-κB) signaling genes and to further check if CGRP in the TG can affect neuron-glia activation in the spinal trigeminal nucleus caudalis. The glial cells of TG were stimulated with CGRP or Minocycline (Min) + CGRP. The effect on various genes involved in NF-κB signaling pathway was analyzed compared to no treatment control condition using a PCR array analysis. CGRP, Min + CGRP or saline was directly injected inside the TG and the effect on gene expression of , and and protein expression of cleaved Caspase3 (cleav Casp3) in the TG, and c-Fos and glial fibrillary acidic protein (GFAP) in the spinal section containing trigeminal nucleus caudalis was analyzed. Results showed that CGRP stimulation resulted in the modulation of several genes involved in the interleukin 1 signaling pathway and some genes of the tumor necrosis factor pathway. Minocycline pre-treatment resulted in the modulation of several genes in the glial cells, including anti-inflammatory genes, and neuronal activation markers. A mild increase in cleav Casp3 expression in TG and c-Fos and GFAP in the spinal trigeminal nucleus of CGRP injected animals was observed. These data provide evidence that glial cells can participate in neuroimmune interaction due to CGRP in the TG via NF-κB signaling pathway.

International Journal of Molecular Sciences


A 10-year analysis of internet search trends of the oral health-seeking behavior of Filipinos


Comparative analysis of education, awareness, and knowledge of dentists and physical therapists in the treatment of temporomandibular disorders

To compare the education, awareness, and knowledge of Filipino dentists and physical therapists (PTs) in terms of temporomandibular disorders (TMDs). A 30-item structured online questionnaire was given to recruited PTs and dentists from January 2019 to December 2019. Welch's -test was used to compare the education, awareness, and knowledge of health professionals. Brown-Forsythe and Welch ANOVA with Games-Howell post hoc were used to compare test scores across the knowledge components. Of the 620 professionals, 46.67% dentists and 6.38% PTs had training in TMD. Professionals with more years of experience and who had previous TMD training were more aware of TMD management. Both dentists and PTs showed the lowest knowledge in TMD pathophysiology. This study showed high awareness but low education and knowledge of Filipino dentists and PTs in TMD management. Improving the educational curriculum and refining the training given by accredited professional organizations is suggested.


Global interest for health professions education: A geographic and temporal analyses through web search differences from 2010-2019

The Internet Journal of Allied Health Sciences and Practice


Analysis of the Filipinos interest in searching online for oral cancer

This study analyzed the health-seeking behavior of Filipinos through relative search volume in Google Trends using oral cancer, mouth cancer, tongue cancer, gum cancer, and lip cancer as predetermined search terms. Comma-separated values files containing relative search volumes of search trends pertaining to oral cancer from 2009 to 2019 were assessed. Brown-Forsythe one-way ANOVA was used to measure differences of oral cancer between years and among months. Repeated measures two-way ANOVA measured differences among the searches for mouth cancer, tongue cancer, gum cancer, and lip cancer through the years. Time series models were fitted and used to forecast search interests. The results revealed that interests in oral cancer were significantly higher in 2019 (43.75±5.5, p<0.05) compared to 2009 (29.0 ± 6.7). In terms of months, searches were higher in February (45.0 ± 6.6) compared to May (24.8 ± 3.4, p=0.015), June (25.3 ± 4.4, p=0.020), and December (26.5 ± 4.0, p=0.038). Search interests for gum cancer and lip cancer remained significantly lower from 2011 to 2019, and tongue cancer from 2016 to 2018 but approximated mouth cancer in 2019. The forecast shows mouth cancer (31.67%), tongue cancer (23.75%), and lip cancer (3.83%) fluctuating through the year, while gum cancer (8%) will remain steady in 2020. Health-seeking behavior through search trends show an increased interest in oral cancer in 2019 and during February. Search interests will fluctuate in 2020, but at the end of the year will decrease for mouth cancer and tongue cancer, will increase for lip cancer, and will remain steady for gum cancer.

Asian Pacific Journal of Cancer Prevention : APJCP


A descriptive study of the regional and time-point changes in the Filipinos' internet search for tooth decay and toothache

Philippine Journal of Health Research and Development


Three-dimensional periodontal tissue regeneration using a bone-ligament complex cell sheet

Periodontal tissue is a distinctive tissue structure composed three-dimensionally of cementum, periodontal ligament (PDL) and alveolar bone. Severe periodontal diseases cause fundamental problems for oral function and general health, and conventional dental treatments are insufficient for healing to healthy periodontal tissue. Cell sheet technology has been used in many tissue regenerations, including periodontal tissue, to transplant appropriate stem/progenitor cells for tissue regeneration of a target site as a uniform tissue. However, it is still difficult to construct a three-dimensional structure of complex tissue composed of multiple types of cells, and the transplantation of a single cell sheet cannot sufficiently regenerate a large-scale tissue injury. Here, we fabricated a three-dimensional complex cell sheet composed of a bone-ligament structure by layering PDL cells and osteoblast-like cells on a temperature responsive culture dish. Following ectopic and orthotopic transplantation, only the complex cell sheet group was demonstrated to anatomically regenerate the bone-ligament structure along with the functional connection of PDL-like fibers to the tooth root and alveolar bone. This study represents successful three-dimensional tissue regeneration of a large-scale tissue injury using a bioengineered tissue designed to simulate the anatomical structure.


Association of masticatory muscle activity with sleep arousal and other concomitant movements during sleep

This study aims to verify the associations among sleep bruxism (SB), sleep arousal (SA) and concurrent body movements. Subjects underwent a standard overnight polysomnography test and audio-video recordings. Sleep quality was evaluated according to the Rechtschaffen and Kales criteria, while SA was determined as per the American Sleep Disorders Association criteria. Analyses were performed by an external institution after masking of the subjects' information. SB was assessed based on the presence/absence of rhythmic masticatory muscle activity (RMMA) episodes, which were identified by using electromyography of the masseter muscle. The observed simultaneous movements included lower leg movement (LLM), swallowing, face scratching, head movement, body movement, eye blinking, coughing, licking, sighing, body scratching, lip sucking, somniloquy and yawning. The LLM was determined visually, as well as through an increase in the tibialis electromyogram signal. Other movements were visually assessed using audio-video recordings. The incidences of all the simultaneous movements were compared between RMMA with intercurrent SA (SAwRMMA; RMMA episode derived from a masseter electromyogram showing more than 10% of maximum voluntary contraction) and SA without RMMA (SAw/oRMMA). Fourteen subjects were included in this study (females/males: 4/10, mean age: 31.5 ± 5.7 years). Among these, LLM, swallowing, body movement, licking, body scratching and lip sucking were frequently observed in SAwRMMA episodes than in SAw/oRMMA episodes, significantly. However, the non-specific simultaneous movements were higher observed in SAw/oRMMA episodes than that in SAwRMMA. Our results suggest that SB is concurrently activated with LLM in relation to arousal.


The role of chemical transmitters in neuron-glia interaction and pain in sensory ganglion

Neuropathic pain (NP) develops because of damage to the peripheral or central nervous system. It results in the hyperalgesia and allodynia. In the recent years, various researchers have studied the involvement of neuro-immune system in causing persistence of pain. The absence of synaptic contacts in the sensory ganglion makes them distinctive in terms of pain related signalling. In sensory ganglia, the neurotransmitters or the other modulators such as inflammatory substances produced by the ganglion cells, because of an injury, are responsible for the cross-excitation between neurons and neuron-glial interaction, thus affecting chemical transmission. This chemical transmission is considered mainly responsible for the chronicity and the persistent nature of neuropathic pain. This review examines the pain signalling due to neurotransmitter or cytokine release within the sensory ganglia. The specific areas focused on include: 1) the role of neurotransmitters released from the somata of sensory neurons in pain, 2) neuron-glia interaction and 3) role of cytokines in neuromodulation and pain.


Infection control in short-term dental missions in Cebu, Philippines

The Journal of the Philippine Dental Association


The evolution of dental education in the Philippines


Proposal of quantitative method for determining occlusal plane

The Journal of Japanese Society of Stomatognathic Function


IL-10 and CXCL2 in trigeminal ganglia in neuropathic pain


Neuropathic pain: the evidence behind the facts


The effects of exercise therapy on painful temporomandibular disorders


Analysis of Bone Marrow-derived Mesenchymal Stem Cell Kinetics after Short-term Stimulation with Tumor Necrosis Factor-α (TNF-α)


一次性および二次性舌痛症患者における睡眠障害の検討—睡眠質問票を用いた調査—

一次性および二次性舌痛症患者における睡眠障害の検討—睡眠質問票を用いた調査—


アンケート調査による顎関節症の病態分類(2013年)の利用状況

アンケート調査による顎関節症の病態分類(2013年)の利用状況

Journal of the Japanese Society for the Temporomandibular Joint


Quality of life and job satisfaction among female dentists in Japan


CGRP induces differential regulation of cytokines from satellite glial cells in trigeminal ganglia and orofacial nociception

Neuron-glia interactions contribute to pain initiation and sustainment. Intra-ganglionic (IG) secretion of calcitonin gene-related peptide (CGRP) in the trigeminal ganglion (TG) modulates pain transmission through neuron-glia signaling, contributing to various orofacial pain conditions. The present study aimed to investigate the role of satellite glial cells (SGC) in TG in causing cytokine-related orofacial nociception in response to IG administration of CGRP. For that purpose, CGRP alone (10 μL of 10 M), Minocycline (5 μL containing 10 μg) followed by CGRP with one hour gap (Min + CGRP) were administered directly inside the TG in independent experiments. Rats were evaluated for thermal hyperalgesia at 6 and 24 h post-injection using an operant orofacial pain assessment device (OPAD) at three temperatures (37, 45 and 10 °C). Quantitative real-time PCR was performed to evaluate the mRNA expression of IL-1β, IL-6, TNF-α, IL-1 receptor antagonist (IL-1RA), sodium channel 1.7 (NaV 1.7, for assessment of neuronal activation) and glial fibrillary acidic protein (GFAP, a marker of glial activation). The cytokines released in culture media from purified glial cells were evaluated using antibody cytokine array. IG CGRP caused heat hyperalgesia between 6-24 h (paired- test, < 0.05). Between 1 to 6 h the mRNA and protein expressions of GFAP was increased in parallel with an increase in the mRNA expression of pro-inflammatory cytokines IL-1β and anti-inflammatory cytokine IL-1RA and NaV1.7 (one-way ANOVA followed by Dunnett's post hoc test, < 0.05). To investigate whether glial inhibition is useful to prevent nociception symptoms, Minocycline (glial inhibitor) was administered IG 1 h before CGRP injection. Minocycline reversed CGRP-induced thermal nociception, glial activity, and down-regulated IL-1β and IL-6 cytokines significantly at 6 h (-test, < 0.05). Purified glial cells in culture showed an increase in release of 20 cytokines after stimulation with CGRP. Our findings demonstrate that SGCs in the sensory ganglia contribute to the occurrence of pain via cytokine expression and that glial inhibition can effectively control the development of nociception.

International Journal of Molecular Sciences


The Cebuano mothers willingness to pay for dental healthcare


咬合不全を伴った重度変形性顎関節症症例

咬合不全を伴った重度変形性顎関節症症例


特別養護老人ホーム入所者における顎関節脱臼の実態調査

特別養護老人ホーム入所者における顎関節脱臼の実態調査


Cross-sectional observational study exploring clinical risk of titanium allergy caused by dental implants

Studies have reported cases of metal allergy caused by titanium-containing materials. We wished to clarify the relationship between titanium allergy and dental implants by describing patients who suffered allergic symptoms after they had received such implants. A total of 270 patients who visited a Dental Metal Allergy Clinic at Tokushima University Hospital from April 2010 to March 2014 were the study cohort. Patch testing with 28 types of metal allergens (including four titanium allergens) was undertaken for patients. A total of 217 patients (80.4 %) exhibited allergy-positive reactions to at least one type of metal allergen. Mercury, palladium, chromium and nickel exhibited a higher prevalence of allergy-positive reactions than other metals. Sixteen patients visited our clinic suffering allergic symptoms after receiving dental implants. Eleven of those patients exhibited allergy-positive reactions for any of the metal allergens, and 4 of these patients had allergy-positive reactions against titanium allergens. The total number of allergy-positive reactions for titanium allergens among all 270 patients was 17 (6.3 %). No patient exhibited a positive reaction only for the titanium allergen. The prevalence of allergy-positive reactions for titanium allergens was lower than for other metal allergens. We suggest examination of pre-implant patients who have a history of hypersensitivity reactions to metals.


Investigation of behavioural factors which vary occlusal contact in Japanese dental students


Posterior disc displacement of the temporomandibular joint -a rare case report

Posterior disc displacement (PDD) of the temporomandibular joint (TMJ) is quite rare. The normal position of a disc is slightly anterior to the condyle, so the chances of disc displacement to the posterior direction are low. A 71-year-old Japanese female reported with a chief complaint of lack of occlusion on the right-side molar teeth. Clinical examination revealed lack of occlusal contact in the right posterior region, nearly normal range of mouth opening (41.0 mm), masseter muscle tenderness, and deviation to the left on opening. MRI of the right TMJ showed PDD in both the open- and closed-mouth position and joint effusion. Conservative treatment with a non-steroidal anti-inflammatory drug, stretch exercise with fingers, and stabilization splint improved symptoms for 9 months. Conservative treatment was effective in managing the patient. A follow-up for 9 months with a repeat MRI was undertaken to monitor the progress.


Metal allergy patient treated by titanium implant denture: A case report with at least 4-year follow-up

Patch testing with metal reagents was positive on female patient with history of metal hypersensitivity after dental treatment. All of the dental restorations with metal components were removed, and subsequent oral rehabilitation utilizing dental implants and metal-free prostheses was carried out. The treatments alleviate the presenting signs and symptoms.


Prevalence of posterior disc displacement of the temporomandibular joint in patients with temporomandibular disorders: a systematic review with meta-analysis

To assess the prevalence of posterior disc displacement (PDD) in patients with temporomandibular disorders (TMD) through a systematic review of the literature and meta-analysis, as well as to assess features associated with PDD such as chief complaint, signs and symptoms, morphologic condyle and disc alterations, and PDD management. A systematic literature search was performed in the US National Library of Medicine's PubMed/MEDLINE and Cochrane Library databases to identify all peer-reviewed, English-language manuscripts related to PDD. A critical appraisal checklist provided by the Joanna Briggs Institute for studies reporting prevalence data was used to assess the quality of the included manuscripts. A meta-analysis was conducted using software MetaXL 5.3 (EpiGear International Pty Ltd) add-in for Microsoft Excel. Pooled prevalence and 95% confidence intervals (CIs) were calculated using the software. Heterogeneity of the included studies was assessed using the Higgins I test and Cochran's Q (with P value; < .05 was considered significant). A total of 21 articles were selected for qualitative data synthesis: 2 case reports, 14 observational studies, and 5 studies that reported PDD in various conditions. Quantitative data analysis was performed for the 14 observational studies, of which 13 reported prevalence with respect to the number of joints affected and 9 reported prevalence with respect to the number of patients affected. The overall pooled prevalence of PDD for the number of joints affected was 0.7% (95% CI: 0.005 to 0.008). The pooled prevalence of PDD for the number of patients was 0.9% (95% CI: 0.007 to 0.011). PDD was found to be associated with osseous changes, including changes in the morphology of the condyle, disc, and articular eminence; osseous abnormalities (erosion, osteophytes); and joint effusion. This meta-analysis showed a very low prevalence rate of PDD in TMD patients. The limited literature did not allow conclusions to be drawn about the PDD-related features.

Journal of Oral & Facial Pain and Headache


Educational effects using a robot patient simulation system for development of clinical attitude

The aim of this study was to assess the effectiveness of improving the attitude of dental students towards the use of a full-body patient simulation system (SIMROID) compared to the traditional mannequin (CLINSIM) for dental clinical education. The participants were 10 male undergraduate dental students who had finished clinical training in the university hospital 1 year before this study started. They performed a crown preparation on an upper pre-molar tooth using SIMROID and CLINSIM as the practical clinical trials. The elapsed time for preparation was recorded. The taper of the abutment teeth was measured using a 3-dimensional shape-measuring device after this trial. In addition, a self-reported questionnaire was collected that included physical pain, treatment safety and maintaining a clean area for each simulator. Qualitative data analysis of a free format report about SIMROID was performed using text mining analysis. This trial was performed twice at 1-month intervals. The students considered physical pain, treatment safety and a clean area for SIMROID significantly better than that for CLINSIM (P < .01). The elapsed time of preparation in the second practical clinical trial was significantly lower than in the first for SIMROID and CLINSIM (P < .01). However, there were no significant differences between the abutment tapers for both systems. For the text mining analysis, most of the students wrote that SIMROID was similar to real patients. The use of SIMROID was proven to be effective in improving the attitude of students towards patients, thereby giving importance to considerations for actual patients during dental treatment.


Time-course observation of patients with arthrosis of the temporomandibular joint on MRI

Patients with arthrosis of the temporomandibular joint are examined by MRI, but fewer cases are followed over time by performing MRI several times. The objective of this study was to investigate the presence or absence and types of changes in the structure of the mandibular condyle and articular disc on MR images over time in patients examined by MRI for the diagnosis of arthritis of the temporomandibular joint in order to clarify the usefulness of performing MRI several times.
 MR images for patients who underwent MRI several times based on the clinical diagnosis of arthrosis of the temporomandibular joint were analyzed.
 Twenty-three patients were examined by MRI twice or more. The shortest and longest intervals between the first and final examinations were 75 and 2,588 days, respectively, and the mean was 735 days. Changes in the bone structure of the mandibular condyle were noted on the first MRI in approximately 63 % and new changes were noted on the final examination in approximately 24 %. In addition, the articular disc position in the closed or open mouth had changed on the later examinationin approximately 15 %.
 Performing MRI several times along the clinical course was found to be useful to diagnose the disease stage, judge the treatment effects, and help predict the outcome in patients with arthrosis of the temporomandibular joint.


Effect of short-term Tumour Necrosis Factor-alpha (TNF-α) -stimulation on the growth and differentiation of MC3T3-E1 osteoblast-like cells


Radiographic investigation of the marginal bone loss on dental implants, a retrospective cohort study

Background: During functional loading, the design of the dental implant may have an effect on the response of marginal bone.
Objectives: The purpose of this study was to report the prevalence of peri-implantitis, and to compare radiographic parameters around Brånemark and Replace Select dental implants and evaluate whether disparities in the morphologic features of these two indistinct implant systems, particularly their abutment-implant attachment, had an influence on the health of surrounding tissues and marginal bone loss (MBL).
Materials and Methods: Collection of data was done at the Department of Fixed Prosthodontics, the Department of Maxillo-Facial Prosthodontics, and Oral Implant Center of Tokushima University Hospital, in Tokushima, Japan; between March 2003 and followed until January 2017. Patients who have been treated with the Replace Select internal type implant and the Brånemark variety were selected as cohort. Marginal bone level measurements were evaluated via periapical and panoramic radiographs taken at regular follow-up visit. These dimensions were calculated, starting from the orientation mark at the implant abutment interface to the bottommost perceived contact area of marginal bone with the aforementioned implant system. The change in the level of bone was estimated by calculating the variation involving an initial reference value and the follow-up values.
Results: An average loss of bone at 0.65 ± 1.51 mm (range 0.36 to 7.89 mm) in the Replace Select group was observed, while in the Brånemark group 0.7 ± 1.32 mm (range 0.62 to 8.64 mm) was observed. Spearman rank correlation exhibited a statistically significant positive correlation between progress of bone loss around implant body and interval from implantation in the Brånemark group, whereas in the Replace Select group it was not significant. The Brånemark group exhibited significant (P = 0.0269) negative correlation of MBL and its diameters, whereas the Replace Select group did not exhibit such correlation.
Conclusion: Within the limits of this study, it can be concluded that deviations in the morphologic attributes of these two diverse implant systems had an influence on the health of surrounding tissues and MBL. The Brånemark implants showed a significant increase in MBL (> 1.8mm) as the time of placement elapses. This marked MBL was greater in females than males, in posterior than in anterior, and in the narrow platform implants than the regular platform implants or the wide platform implants. On the other hand, results suggested that this bone loss was greater in the mandible than the maxilla, in single-unit implant crowns than multiple implant restorations in the Replace Select group.

Background: During functional loading, the design of the dental implant may have an effect on the response of marginal bone.Objectives: The purpose of this study was to report the prevalence of peri-implantitis, and to compare radiographic parameters around Brånemark and Replace Select dental implants and evaluate whether disparities in the morphologic features of these two indistinct implant systems, particularly their abutment-implant attachment, had an influence on the health of surrounding tissues and marginal bone loss (MBL).Materials and Methods: Collection of data was done at the Department of Fixed Prosthodontics, the Department of Maxillo-Facial Prosthodontics, and Oral Implant Center of Tokushima University Hospital, in Tokushima, Japan; between March 2003 and followed until January 2017. Patients who have been treated with the Replace Select internal type implant and the Brånemark variety were selected as cohort. Marginal bone level measurements were evaluated via periapical and panoramic radiographs taken at regular follow-up visit. These dimensions were calculated, starting from the orientation mark at the implant abutment interface to the bottommost perceived contact area of marginal bone with the aforementioned implant system. The change in the level of bone was estimated by calculating the variation involving an initial reference value and the follow-up values.Results: An average loss of bone at 0.65 ± 1.51 mm (range 0.36 to 7.89 mm) in the Replace Select group was observed, while in the Brånemark group 0.7 ± 1.32 mm (range 0.62 to 8.64 mm) was observed. Spearman rank correlation exhibited a statistically significant positive correlation between progress of bone loss around implant body and interval from implantation in the Brånemark group, whereas in the Replace Select group it was not significant. The Brånemark group exhibited significant (P = 0.0269) negative correlation of MBL and its diameters, whereas the Replace Select group did not exhibit such correlation.Conclusion: Within the limits of this study, it can be concluded that deviations in the morphologic attributes of these two diverse implant systems had an influence on the health of surrounding tissues and MBL. The Brånemark implants showed a significant increase in MBL (> 1.8mm) as the time of placement elapses. This marked MBL was greater in females than males, in posterior than in anterior, and in the narrow platform implants than the regular platform implants or the wide platform implants. On the other hand, results suggested that this bone loss was greater in the mandible than the maxilla, in single-unit implant crowns than multiple implant restorations in the Replace Select group.


An investigation of the Filipino dental students' personality types

Philippine Journal of Health Research and Development


咬合違和感の診断と対処法

咬合違和感の診断と対処法


Organizational dilemma: Dental faculty acquisition in the Philippines


Technology acceptance model in the use of a patient management software in a dental school in the Philippines

IOSR Journal of Dental and Medical Sciences


A Philippine rural schools organizational climate, teachers performance, and management competencies

International Journal of Research -GRANTHAALAYAH


Filipino teachers sense of efficacy inclusion classes


Validity of peer evaluation for team-based learning in a dental school in Japan

The aim of this study was to determine the validity of peer evaluation for team-based learning (TBL) classes in dental education in comparison with the term-end examination records and TBL class scores. Examination and TBL class records of 256 third- and fourth-year dental students in six fixed prosthodontics courses from 2013 to 2015 in one dental school in Japan were investigated. Results of the term-end examination during those courses, individual readiness assurance test (IRAT), group readiness assurance test (GRAT), group assignment projects (GAP), and peer evaluation of group members in TBL classes were collected. Significant positive correlations were found between all combinations of peer evaluation, IRAT, and term-end examination. Individual scores also showed a positive correlation with group score (total of GRAT and GAP). From the investigation of the correlations in the six courses, significant positive correlations between peer evaluation and individual score were found in four of the six courses. In this study, peer evaluation seemed to be a valid index for learning performance in TBL classes. To verify the effectiveness of peer evaluation, all students have to realize the significance of scoring the team member's performance. Clear criteria and detailed instruction for appropriate evaluation are also required.


Frequency of congenitally missing permanent teeth at a primary dental care clinic in Tokushima, Japan

The Journal of Japan Association of Oral Rehabilitation


Effects of Custom-made Mouthguard Use on Physical Performance and Concentration

The International Journal of Sports Dentistry


Complications causing patients to discontinue using oral appliances for treatment of obstructive sleep apnea

Oral appliances (OAs) are commonly used as a noninvasive treatment for obstructive sleep apnea syndrome (OSAS). These devices are worn during sleep and create mandibular anterior traction to enlarge the upper airway. Continuous use of the device is essential for the success of OA therapy, but some patients stop using the OA for various reasons. The purpose of this research was to investigate complications in OA therapy that might prevent continuous use of these devices. The progress of 90 OSAS patients who visited Tokushima University Hospital and underwent OA therapy was investigated with a mailed questionnaire. All patients had been receiving OA therapy for more than 12 months. Forty patients responded to the questionnaire and of these, 22 were not wearing their OA during sleep. The average period before stopping OA therapy was 9.6 months. Answers from 38 patients who were treated with two-piece Herbst(®)-type oral appliances were analyzed. The main reasons for stopping OA therapy were: (1) it was bothersome to use; and (2) it did not effectively prevent sleep apnea. Comparison of OA complications between current OA users and nonusers revealed significant differences for the items "difficulty sleeping" and "stifling feeling". OA users recorded better scores for sleep quality than nonusers. The results of this study indicate that patients discontinued OA therapy because the appliance was "bothersome to use" and because it had "little or no effect" rather than because they experienced the typical complications of OA therapy.


Comparison between flipped classroom and team-based learning in fixed prosthodontic education


Reliability and validity of the patient disability-oriented diagnostic nomenclature system for prosthetic dentistry

The Japan Prosthodontic Society (JPS) has proposed a new diagnostic nomenclature system (DNS), based on pathogenesis and etiology, to facilitate and improve prosthodontic treatment. This system specifies patient disability and the causative factor (i.e. "B (disability) caused by A (causative factor)"). The purpose of this study was to examine the reliability and validity of this DNS. The JPS Clinical Guideline Committee assessed mock patient charts and formulated disease names using the new DNS. Fifty validators, comprising prosthodontic specialists and dental residents, made diagnoses using the same patient charts. Reliability was evaluated as the consistency of the disease names among the validators, and validity was evaluated using the concordance rate of the disease names with the reference disease names. Krippendorff's α was 0.378 among all validators, 0.370 among prosthodontic specialists, and 0.401 among dental hospital residents. Krippendorff's α for 10 validators (3 specialists and 7 residents) with higher concordance rates was 0.524. Two validators (1 specialist and 1 resident) with the highest concordance rates had a Krippendorff's α of 0.648. Common disease names had higher concordance rates, while uncommon disease names showed lower concordance rates. These rates did not show correlation with clinical experience of the validator or time taken to devise the disease name. High reliability was not found among all validators; however, validators with higher concordance rates showed better reliability. Furthermore, common disease names had higher concordance rates. These findings indicate that the new DNS for prosthodontic dentistry exhibits clinically acceptable reliability and validity.


Mandibular movement during sleep bruxism associated with current tooth attrition

Observation of attrition patterns suggests that mandibular movement in sleep bruxism (SB) may be associated with current tooth attrition. The aim of this study was to confirm this phenomenon by investigating mandibular movement and masseter muscle activity. The subject was a healthy 21-year-old Japanese male. We recorded biological signals including mandibular movement and masseter electromyograms (EMGs) with a polysomnograph. Based on the EMG using Okura's criteria, SB events were classified into clenching, grinding and mixed types according to mandibular movement criteria. The close-open mandibular movement cycles (CO-cycles) during grinding and mixed type events were selected based on mandibular movement trajectories. Fifty-eight CO-cycles were selected in seven grinding and three mixed types. We found that SB mandibular movements associated with current tooth attrition. Excessive lateral movements (ELM) beyond the canine edge-to-edge position were observed in the closing (10.3%) and opening (13.8%) phases of the CO-cycle. Total masseter muscle activity was significantly higher during voluntary grinding (VGR) than during CO-cycle including ELM (working side: P=0.036, balancing side: P=0.025). However, in the middle and late parts of the opening phase, working side masseter muscle activity was significantly higher during CO-cycle including ELM than during VGR (P=0.012). In the early part of the closing phase, balancing side masseter muscle activity was significantly higher during CO-cycle including ELM than during VGR (P=0.017). These findings suggest that excessive forceful grinding during ongoing SB events may have caused canine attrition in this patient.


Investigation of Effect on Physical Performance and Concentration by Custom-made Mouthguard Use

International Journal of Sports Dentistry


Glossopharyngeal Neuralgia Caused by Diabetes Mellitus

糖尿病神経障害と診断された舌咽神経痛の一症例


Preliminary study of neural excitation with positron emission tomography after tooth mechanical stimulation

Dentists often cannot objectively find abnormalities in patients who complain of discomfort or abnormal sensation in their dental occlusion. We hypothesized that abnormal neural transmission from the tooth is related to this occlusal discomfort sensation. Chronic tooth contact habits may induce neural excitation from the tooth to the central nervous system, and may aggravate the sensation of discomfort in the central nervous system. However, the details of neural transmission from the tooth to the central nervous system are still unclear. In this study, we stimulated a rat premolar mechanically and observed activated bran sites using positron emission tomography (PET) and 18F-2-fluoro-2-deoxy-D-glucose (FDG). We anesthetized 5-7-week-old male rats using isoflurane inhalation anesthesia and stimulated the upper right premolar mechanically with an electric von Frey system (Model 1601C, IITC Instruments) by measuring mechanical pressure. Before the tooth mechanical stimulation, we injected FDG through the rat's caudal vein and then used a stimulation intensity of 100, 200 or 300 g. We recorded FDG accumulation with PET. The PET brain images were separated into four parts (right higher, left higher, right lower and left lower) for analysis and the peak value of striatal uptake (SUV) in each part was analyzed. The PET images showed that the accumulated FDG in the right lower part of the brain was higher with 300 g tooth stimulation than with 100 or 200 g. The data showed that the tooth stimulation site in the lower part of the brain was activated with tooth stimulation by comparing it with the other parts. We also measured SUV in the right and left sensory areas, motor area, hippocampus, trigeminal ganglia (TG) and spinal cord. The TG and sensory area showed more FDG accumulation compared with mouth opening.


Relationship between the mandibular movements and deformation of the coronoid process and the condyle


The effect of splints on sleep bruxism : a preliminary study

スプリントによる睡眠時ブラキシズムに対する治療効果 : 予備的検討

The Journal of Japan Association of Oral Rehabilitation

日本口腔リハビリテーション学会雑誌


睡眠時ブラキシズムの基礎と最新の捉え方

睡眠時ブラキシズムの基礎と最新の捉え方


Japan Prosthodontic Society position paper on occlusal discomfort syndrome

Dentists may encounter patients who present with a sense of a malocclusion but in whom no objective findings can be detected. For the patient who insists that there is occlusal discomfort, in the absence of evidence some dentists elect to perform an occlusal adjustment that not only fails to alleviate symptoms, and may, in fact, exacerbate the discomfort. The patient-dentist relationship is then likely compromised because of a lack of trust. In 2011, the Clinical Practice Guidelines Committee of the Japan Prosthodontic Society formulated guidelines for the management of occlusal discomfort. When formulating clinical practice guidelines, the committee bases their recommendations on information derived from scientific evidence. For "occlusal dysesthesia," however, there are an insufficient number of high-quality papers related to the subject. Therefore, a consensus meeting was convened by the Japan Prosthodontic Society to examine evidence in the Japanese- and English-language literature and generate a multi-center survey to create an appropriate appellation for this condition. As a result of the consensus meeting and survey findings, this condition may be justifiably termed "occlusal discomfort syndrome." The Japan Prosthodontics Society believes that identification of an umbrella term for occlusal discomfort might serve as a useful guide to formulating clinical practice guidelines in the future. This position paper represents summary findings in the literature combined with the results of a multicenter survey focused on dental occlusal treatment and the condition of patients who present with occlusal discomfort syndrome.


口腔ならびに呼吸器症状を呈した歯科用金属によるアレルギーの1例

口腔ならびに呼吸器症状を呈した歯科用金属によるアレルギーの1例

Journal of Japanese Society for Evidence and the Dental Professional


Allergic contact dermatitis caused by titanium screws and dental implants

Titanium has been considered to be a non-allergenic material. However, several studies have reported cases of metal allergy caused by titanium-containing materials. We describe a 69-year-old male for whom significant pathologic findings around dental implants had never been observed. He exhibited allergic symptoms (eczema) after orthopedic surgery. The titanium screws used in the orthopedic surgery that he underwent were removed 1 year later, but the eczema remained. After removal of dental implants, the eczema disappeared completely. Titanium is used not only for medical applications such as plastic surgery and/or dental implants, but also for paints, white pigments, photocatalysts, and various types of everyday goods. Most of the usage of titanium is in the form of titanium dioxide. This rapid expansion of titanium-containing products has increased percutaneous and permucosal exposure of titanium to the population. In general, allergic risk of titanium material is smaller than that of other metal materials. However, we suggest that pre-implant patients should be asked about a history of hypersensitivity reactions to metals, and patch testing should be recommended to patients who have experienced such reactions.


下顎大臼歯欠損に対しインプラント支持固定性補綴装置による治療介入時に付与すべき咬合様式

Clinical guidelines or definitive criteria for "Occlusal consideration for fixed implant prosthesis in mandibular posterior region" have not been established yet although the dental implant is an essential treatment option for current prosthetic dentistry. This position paper aimed to propose a critical recommendation and consequently indicate a tentative practice guideline. In this paper, the first and second molar missing in the mandible was assumed as the most typical partial edentulous jaw. A panel of clinical experts concerning dental implant practice was selected from the members of the Japan Prosthodontic Society, and a meeting was held to collect clinical data obtained from daily practice and to estimate expert opinions. As a result, general remarks were presented regarding shapes of prostheses, position and number of occlusal contact points, occlusal contact during lateral excursion, displacement of periodontal ligament, and materials of occlusal surface. However, the expert opinions described above have not been supported by clinical evidence. Moreover, neither the effect of those therapies nor long-term prognosis has been thoroughly investigated. Thus, further study for collecting the clinical evidences is required to formulate the clinical guideline.

インプラント治療が補綴歯科臨床の場で必要不可欠となった今日においても，未だ「インプラント支持固定性補綴装置に付与すべき咬合様式」のガイドラインまたは明確な基準は示されていない．本ポジションペーパーにおいては，その推奨されるべき一定の基準を示し，臨床上の指針として提案することを目的とした．本稿では，典型的な欠損形態である下顎大臼歯部欠損にインプラント支持補綴装置を装着した場合を想定している．口腔インプラントを適用した治療に関して経験豊富なエキスパートパネルを，(公社)日本補綴歯科学会会員から選出し，臨床の現場における事象を検証した結果として得られた意見を集積し，パネル会議で検討した．その結果，補綴装置の形態，咬合接触点の位置と数，側方運動時の咬合接触の有無，歯根膜の変位量の考慮，補綴装置咬合面の材料等に関する知見が得られ，推奨される一定の基準が示された．しかしながら，上記内容は明確な根拠に支持されるものではなく，治療効果と術後経過に関する研究が不十分であり，今後さらなる知見の集積と検証のもとに，ガイドラインを策定すべきである．


Sleep bruxism frequency and platelet serotonin transporter activities in young adult subjects

To evaluate correlations between serotonin transporter (SERT) uptake ability in human peripheral platelets and sleep bruxism (SB) frequency. Subjects were consecutively recruited from sixth-year students at Okayama University Dental School. Subjects were excluded if they (1) were receiving orthodontic treatment, (2) had a dermatological disease, (3) had taken an antidepressant within 6 months, or (4) had used an oral appliance within 6 months. SB frequency was determined as the summary score of three consecutive night assessments using a self-contained electromyography detector/analyzer in their home. Fasting peripheral venous blood samples were collected in the morning following the final SB assessment. SERT amount and platelet number were quantified via an ELISA assay and flow cytometry, respectively. Functional SERT characterization, 5-hydroxytryptamine (5-HT) uptake, maximum velocity (V max), and an affinity constant (K m ) were assessed with a [(3)H] 5-HT uptake assay. The correlations between these variables and SB level were evaluated. Among 50 eligible subjects (26 males, mean age 25.4 ± 2.41 years), 7 were excluded because of venipuncture failure, smoking, and alcohol intake during the experimental period. A small but significant negative correlation between SB level and [(3)H] 5-HT uptake was observed (Spearman's correlation R (2) = 0.063, p = 0.04). However, there were no significant correlations between SB level and total platelet amount, SERT, V max, and K m values (p = 0.08, 0.12, 0.71, and 0.68, respectively). Platelet serotonin uptake is significantly associated with SB frequency, yet only explains a small amount of SB variability.


根尖性歯周炎に起因した放射線性下顎骨骨髄炎に対して保存的治療を行い良好な経過を得た一症例

The Japanese Journal of Conservative Dentistry


Masticatory performance alters stress relief effect of gum chewing

We evaluated the effects of gum chewing on the response to psychological stress induced by a calculation task and investigated the relationship between this response and masticatory performance. Nineteen healthy adult volunteers without dental problems undertook the Uchida-Kraepelin (UK) test (30min of reiterating additions of one-digit numbers). Before and immediately after the test, saliva samples were collected from the sublingual area of the participants. Three min after the UK test, the participants were made to chew flavorless gum for 3min, and the final saliva samples were collected 10min after the UK test. The experiment was performed without gum chewing on a different day. Masticatory performance was evaluated using color-changing chewing gum. Salivary CgA levels at immediately and 10min after the UK test were compared with and without gum chewing condition. Two-way repeated measures analysis of variance revealed significant interaction between gum chewing condition and changes in CgA levels during post 10min UK test period. A significant correlation was found between changes in CgA levels and masticatory performance in all participants. Our results indicate that gum chewing may relieve stress responses; however, high masticatory performance is required to achieve this effect.


Cross-excitation in peripheral sensory ganglia is associated with pain transmission

Despite the absence of synaptic contacts, cross-excitation of neurons in sensory ganglia during signal transmission is considered to be chemically mediated and appears increased in chronic pain states. In this study, we modulated neurotransmitter release in sensory neurons by direct application of type A botulinum neurotoxin (BoNT/A) to sensory ganglia in an animal model of neuropathic pain and evaluated the effect of this treatment on nocifensive. Unilateral sciatic nerve entrapment (SNE) reduced the ipsilateral hindpaw withdrawal threshold to mechanical stimulation and reduced hindpaw withdrawal latency to thermal stimulation. Direct application of BoNT/A to the ipsilateral L4 dorsal root ganglion (DRG) was localized in the cell bodies of the DRG and reversed the SNE-induced decreases in withdrawal thresholds within 2 days of BoNT/A administration. Results from this study suggest that neurotransmitter release within sensory ganglia is involved in the regulation of pain-related signal transmission.


A preliminary investigation of reproducibility of EMG signals during daytime masticatory muscle activity using a portable EMG logging device

Journal of Electromyography and Kinesiology


A longitudinal retrospective study of the analysis of the risk factors of implant failure by the application of generalized estimating equations

Many studies have identified risk factors for dental implant failure, although few have investigated the correlation among implant fixtures within single patients. A better analytical method may include repeated measures analysis including generalized estimating equations (GEE). This retrospective cohort study aimed to (1) identify the risk factors for failure of dental implantation and (2) evaluate an analytical method using GEE analysis. We analyzed data on early and late implant failures in 296 patients providing 721 rough surface dental implants (2.44 implants per patient). Potential predictors of implant failure included age, gender, smoking, location of implant, use of bone augmentation, number of remaining teeth, opposing tooth condition, fixture length, fixture diameter and type of suprastructure (fixed or removable partial denture). The likelihood of early and late implant failure was estimated by GEE. The early failure rate was 1.5% (11/721 implants, 7/296 patients) and the 10-year cumulative survival rate was 94.0% (7/710 implants, 5/293 patients). The GEE analysis revealed that a significant risk factor for early implant failure was smoking (p<0.01), whereas significant risk factors for late failure were maxillary implant (p=0.02), posterior implant (p<0.01), number of remaining teeth (≥20) (p<0.01), opposing unit being a removable partial denture or nothing (p=0.04) and having a removable type suprastructure (p<0.01). GEE analysis showed that smoking was a risk factor for early implant failure, and several risk factors were identified for late implant failure.


Diagnosis and treatment for obstructive sleep apnea: Fundamental and clinical knowledge in obstructive sleep apnea

This review article covers the diagnosis and treatment of obstructive sleep apnea (OSA) from a dental perspective. It addresses the issue of when and how to screen for and then, if indicated, refer the patient for a more comprehensive. Our focus in this article was on identifying current unanswered questions that relevant to OSA problems that dental scientists have to pursue and on providing valuable information on that problems, consequently the previous studies which investigated or reviewed the diagnosis and treatment of OSA were included. In addition, we included studies on jaw movements during sleep and on the use of a lateral cephalometric film related to the diagnosis and treatment of OSA. The role of portable sleep monitoring devices versus full laboratory polysomnography is discussed. This review also describes what is known about the efficacy of mandibular advancement devices and when and how they fit in to a treatment program for a patient with obstructive sleep apnea. Finally some basic research is presented on jaw movements during sleep and how a lateral cephalometric film can be used to assess the changes of the airway with body posture and head posture. This article provides the valuable suggestions for the clinical questions in the diagnosis and treatment of OSA.


Effects of team-based learning on fixed prosthodontic education in Japan

The aims of this study were to evaluate the quality of team-based learning (TBL) in prosthodontics education for fourth-year dental students at Tokushima University School of Dentistry and to compare this teaching method with traditional lecture-based delivery. Participants in the study were 36 students (22 males and 14 females) who attended the TBL-style fixed prosthodontics course. Ten 60-minute classes were held. The first three were traditional lecture-style classes and were followed by one class introducing the TBL style. The remaining six classes constituted the TBL-format fixed prosthodontics course. The effectiveness of TBL was evaluated through student questionnaires at the end of each class and the results of the term-end examination. The questionnaire revealed high student approval for TBL-style learning, and active group discussion among students during TBL was a key factor in these ratings. In the results of the term-end examination, there were significantly higher scores on the questions that covered TBL-taught material than those covering traditional lecture-taught topics. The results of this study suggest that TBL-style lecture was more effective than traditional-style lecture for teaching fixed prosthodontics and that TBL was a more efficient mode of delivering dental education than traditional lecture-based teaching.


Introduction and Effects of Team-Based Learning on Prosthodontic Education

歯科補綴学授業におけるTeam-Based Learningの導入とその効果

Team-Based Learning (TBL) was introduced into our prosthodontic education for thirdyear dental school students. Forty students (26 males and 14 females) of Tokushima University School of Dentistry attended the TBL-style fixed prosthodontic course. A total of fifteen classes (60 minutes each), which started with six conventional lecture-style classes followed by 8 TBL-style classes, were held. The effectiveness of TBL was evaluated with student questionnaires at the end of each class and with the results of the term-end examination. The results of the questionnaire on some questions and term-end examination exhibited higher score for the TBL. The results of this study showed that TBL-style classes were more effective than that of the conventional lecture-style classes for the fixed prosthodontic course.


Basic research and clinical investigations of the neural basis of orofacial pain


Establishment of a method for measuring and analyzing various bio-information during a sequence of feeding : Development of a measuring system

摂食・咀嚼・嚥下過程における各種生体情報の記録解析法の開発 ―測定システムの開発―

The Journal of Japan Association of Oral Rehabilitation

日本口腔リハビリテーション学会雑誌


Development of a new method for understanding visually slight tooth movements with six-degree-of-freedom

歯の6自由度運動を視覚的に理解する手法の開発

日本口腔リハビリテーション学会雑誌


咬合違和感を訴える患者の実態に関する多施設実態調査

咬合違和感を訴える患者の実態に関する多施設実態調査

Journal of the Japanese Society for the Temporomandibular Joint


A proposed core curriculum for dental English education in Japan.

Globalization of the professions has become a necessity among schools and universities across the world. It has affected the medical and dental professions in terms of curriculum design and student and patient needs. In Japan, where medicine and dentistry are taught mainly in the Japanese language, profession-based courses in English, known as Medical English and Dental English, have been integrated into the existing curriculum among its 83 medical and 29 dental schools. Unfortunately, there is neither a core curriculum nor a model syllabus for these courses. This report is based on a survey, two discussion forums, a workshop, and finally, the drafting of a proposed core curriculum for dental English approved by consensus of the participants from each university. The core curriculum covers the theoretical aspects, including dental English terms and oral pathologies; and practical aspects, including blended learning and dentist-patient communication. It is divided into modules and is recommended to be offered for at least two semesters. The core curriculum is expected to guide curriculum developers in schools where dental English courses are yet to be offered or are still in their early development. It may also serve as a model curriculum to medical and dental schools in countries in Asia, Europe, Africa, and Central and South America, where English is not the medium of instruction.


Systematic review and recommendations for nonodontogenic toothache

Nonodontogenic toothache is a painful condition that occurs in the absence of a clinically evident cause in the teeth or periodontal tissues. The purpose of this review is to improve the accuracy of diagnosis and the quality of dental treatment regarding nonodontogenic toothache. Electronic databases were searched to gather scientific evidence regarding related primary disorders and the management of nonodontogenic toothache. We evaluated the level of available evidence in scientific literature. There are a number of possible causes of nonodontogenic toothache and they should be treated. Nonodontogenic toothache can be categorised into eight groups according to primary disorders as follows: 1) myofascial pain referred to tooth/teeth, 2) neuropathic toothache, 3) idiopathic toothache, 4) neurovascular toothache, 5) sinus pain referred to tooth/teeth, 6) cardiac pain referred to tooth/teeth, 7) psychogenic toothache or toothache of psychosocial origin and 8) toothache caused by various other disorders. We concluded that unnecessary dental treatment should be avoided.


Comparison of platelet serotonin transporter activity in subjects with severe sleep bruxism and control

The aim of this study was to evaluate the correlation between sleep bruxism (SB) frequency and serotonin transporter (SERT)-driven serotonin (5-HT)-uptake in platelets. Subjects were dental trainee residents and faculty members of Okayama University Hospital who were aware of having severe or no SB. SB frequency was assessed for 3-consecutive nights by a self-contained electromyographic detector/analyzer, which indicated individual SB levels as one of four grades (score 0, 1, 2 and 3). Subjects were classified as normal control (NC) when SB scores indicated only 0 or 1 during the 3 nights, or as severe SB for scores 2 or 3. Those subjects whose scores fluctuated from 0 to 3 during the 3 nights were omitted from further analysis. Fasting peripheral venous blood samples were collected in the morning following the final SB assessment. Amounts of SERTs proteins collected from peripheral platelets were quantified using ELISA, and SERTs transport activity was assessed by uptake assay using [(3)H]-5-HT. Thirteen severe SB subjects and 7 NC subjects were eligible. Gender distribution, mean age, 5-HT concentration and total amounts of SERT protein in platelets showed no significant differences between NC and severe SB (p=0.85: Chi-squared test; p=0.64, 0.26, 0.46: t-test). However, [(3)H]-5-HT uptake by platelets was significantly greater in NC compared to severe SB subjects (12.79±1.97, 8.27±1.91fmol/10(5) platelets/min, p<0.001, t-test). The results of this pilot study suggest a possible correlation between peripheral platelet serotonin transporter uptake ability and SB severity.