Essence of diagnosis and management of sleep bruxism


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.


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

International Journal of Sports Dentistry


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


Managements of sleep bruxism in adult: A systematic review.

This systematic review aimed to update the management of sleep bruxism (SB) in adults, as diagnosed using polysomnography (PSG) and/or electromyography (EMG). Management methods covered were oral appliance therapy (OAT) with stabilization splints, cognitive-behavioral therapy (CBT), biofeedback therapy (BFT), and pharmacological therapy. A comprehensive search was conducted on MEDLINE, Cochrane Library, and Web of Science up to October 1st, 2021. Reference list searches and hand searches were also performed by an external organization. Two reviewers for each therapy independently performed article selection, data extraction, and risk of bias assessment. The reviewers resolved any disagreements concerning the assortment of the articles by discussion. Finally, 11, 3, 14, and 22 articles were selected for each therapy. The results suggested that OAT tended to reduce the number of SB events, although there was no significant difference compared to other types of splints, that the potential benefits of CBT were not well supported, and that BFT, rabeprazole, clonazepam, clonidine, and botulinum toxin type A injection showed significant reductions in specific SB parameters, although several side effects were reported. It can be concluded that more methodologically rigorous randomized large-sample long-term follow-up clinical trials are needed to clarify the efficacy and safety of management for SB.


Botulinum toxin injection attenuates nonodontogenic toothache: A case report


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


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.


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.


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).


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.


Changes in oxygen and carbon dioxide in the genesis of sleep bruxism:a mechanism study

Rhythmic masticatory muscle activity (RMMA), a biomarker of sleep bruxism (SB), has been associated with mild hypoxia and/or big breaths in some adults with non-sleep-disordered breathing. The purpose of this study was to investigate that concurrent oxygen and carbon dioxide fluctuations are among the physiological variables that contribute to RMMA onset. Twelve subjects (5 female, 7 male, mean age: 43 ± 11) underwent polysomnography recording in a sleep laboratory. RMMA index and apnea-hypopnea index were calculated. Oxygen saturation (SpO) was estimated by finger pulse oximeter and end-tidal CO (ETCO) by nasal airflow cannula before and after RMMA onset. Given the expected response time delay between actual arterial hypoxemia and fingertip pulse detection, we adjusted the SpO desaturation onset to the onset of masseter muscle activity using a 17 s criterion based on ETCO shifts. SpO was slightly but significantly lower than at baseline (max: -0.6%) in the 6-4 s before RMMA onset and significantly higher in the 6-18 s after onset (0.9%; p < 0.05). Although ETCO before RMMA onset did not differ from baseline, it decreased at 8-10 s after onset (-1.7 mmHg: p < 0.05). No changes in SpO or ETCO in relation to RMMA onset reached a critical clinical threshold. The mild transient hypoxia observed before RMMA onset was not associated with a change in ETCO The mild and brief oxygen fluctuations before RMMA onset may reflect a physiological response that seems to have little influence on SB genesis.


The effects of exercise therapy on painful temporomandibular disorders


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—


Quality of life and job satisfaction among female dentists in Japan


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

The Journal of Japanese Society of Stomatognathic Function


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.


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


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


Comparison between flipped classroom and team-based learning in fixed prosthodontic education Journal of Prosthodontic Research


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


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.


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

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


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.


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.


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


Effect of an exclusion range of jaw movement data from the intercuspal position on the estimation of the kinematic axis point

In patients who have lost natural occlusal contacts, the centric relation is usually estimated based on several anatomical factors such as the temporomandibular joint and masticatory muscles except dental arch. The clinical procedure to record the centric relation often depends on the clinician's expertise and technique; an objective method to determine proper occlusal position is desirable. The kinematic axis point (KAP) is kinematically estimated from sagittal movements and is an ideal posterior reference point that is used in dental articulators for reproducing jaw movement. Occlusal registration using the KAP may serve as a definite objective technique. The aim of this study is to investigate the effect of the exclusion range of sagittal jaw movement data from the intercuspal position (ICP) on the estimation of the KAP. The complete and incomplete sagittal border movement data of dentate subjects were used to estimate the KAPs. The locations of the estimated KAPs were compared. The results indicate that the incomplete sagittal border jaw movement data set does not include data points inside a 7mm distance from the ICP can be used for estimation of the KAP. In conclusion, the sagittal border jaw movement data around the ICP is not indispensable in the valid identification of the KAP.


Mandibular Movement during Sleep Bruxism: Mandibular Position with Peak Masseter Muscle Activity

The Journal of Japan Association of Oral Rehabilitation


Sleep less and bite more: Sleep disorders associated with occlusal loads during sleep.

Occlusal overload during sleep is a significant clinical issue that has negative impacts on the maintenance of teeth and the longevity of dental prostheses. Sleep is usually viewed as an 'out-of-functional' mode for masticatory muscles. However, orodental structures and prostheses are not free from occlusal loads during sleep since masticatory muscles can be activated at a low level within normal sleep continuity. Thus, an increase in masticatory muscle contractions, by whatever the cause, can be associated with a risk of increased occlusal loads during sleep. Among such conditions, sleep bruxism (SB) is a type of sleep-related movement disorders with potential load challenge to the tooth and orofacial structures. Patients with SB usually report frequent tooth grinding noises during sleep and there is a consecutive increase in number and strength of rhythmic masticatory muscle activity (RMMA). Other types of masticatory muscle contractions can be non-specifically activated during sleep, such as brief contractions with tooth tapping, sleep talking, non-rhythmic contractions related to non-specific body movements, etc.; these occur more frequently in sleep disorders. Studies have shown that clinical signs and symptoms of SB can be found in patients with sleep disorders. In addition, sleep becomes compromised with aging process, and a prevalence of most sleep disorders is high in the elderly populations, in which prosthodontic rehabilitations are more required. Therefore, the recognition and understanding of the role of sleep disorders can provide a comprehensive vision for prosthodontic rehabilitations when prosthodontists manage complex orodental cases needing interdisciplinary collaborations between dentistry and sleep medicine.


Abstract Symposium: The patterns of close-open jaw movement during sleep in normal subjects


睡眠中の咀嚼筋安静状態における垂直的顎位-スプリントの最適な咬合挙上量の検討-

睡眠中の咀嚼筋安静状態における垂直的顎位-スプリントの最適な咬合挙上量の検討-

The Journal of Japanese Society of Stomatognathic Function


Gender specificity of the slow wave sleep lost in chronic widespread musculoskeletal pain.

The majority of patients suffering from musculoskeletal chronic widespread pain (CWP) are females, and they tend to report poor sleep. We tested the hypothesis that the poor sleep of female patients reporting CWP is gender specific for changes in (1) electroencephalograph (EEG) features and (2) heart rate variability (HRV).


Verification of kinematic condylar point


切除からインプラントを維持源としたエピテーゼまで一貫治療を行った上顎洞悪性線維性組織球腫の1例


Study on measurement and Analysis of Jaw Movements during Sleep Bruxism

睡眠時ブラキシズム発現に伴う顎運動の測定解析法の検討


Current status of researches on jaw movement and occlusion for clinical application


ミリングテクニックを用い審美性に配慮した部分欠損補綴の1症例

ミリングテクニックを用い審美性に配慮した部分欠損補綴の1症例


Genesis of sleep bruxism: motor and autonomic-cardiac interactions

This is a short review paper presenting hypothesis to explain the mechanism that may be involved in the genesis of sleep bruxism (SB). In humans, SB is a repetitive sleep movement disorder mainly characterized by rhythmic masticatory muscle activity (RMMA) at a frequency of 1Hz and by occasional tooth grinding. Until recently, the mechanism by which RMMA and SB episodes are triggered has been poorly understood. It is reported that during light sleep, most SB episodes are observed in relation to brief cardiac and brain reactivations (3-15s) termed "micro-arousals". We showed that RMMA are secondary to a sequence of events in relation to sleep micro-arousals: the heart (increase in autonomic sympathetic activity) and brain are activated in the minutes and seconds, respectively, before the onset of activity in suprahyoid muscles and finally by RMMA in jaw closing masseter or temporalis muscles. In non-human primate study, we have shown that the excitability of cortico-bulbar pathways is depressed during sleep; no rhythmic jaw movements (RJM) are observed following intracortical microstimulation (ICMS) of cortical masticatory area (CMA) during sleep compared to the quiet awake state. The above results suggest that the onset of RMMA and SB episodes during sleep are under the influences of brief and transient activity of the brainstem arousal-reticular ascending system contributing to the increase of activity in autonomic-cardiac and motor modulatory networks.


Comparison of various treatments for sleep bruxism using determinants of number needed to treat and effect size.

PURPOSE: Sleep bruxism (SB) is associated with temporomandibular pain, headaches, tooth wear, and disruption of the bed partner's sleep. The aim of this report was to compare SB treatments from various experimental studies to guide the selection of a treatment for a large sample size study. MATERIALS AND METHODS: After a literature search, randomized controlled studies of 7 pharmacologic treatments and 3 oral devices were included. The number needed to treat (NNT) was calculated from raw data from the sleep laboratory at the Hôpital du Sacré-Coeur, Montréal or from published articles when sufficient data were available. The effect size (ES) was calculated for all included studies. In the most effective treatments, the NNT ranged from 1 to 4, while a high ES was above 0.8. RESULTS: The treatments with the best NNT and ES results were the mandibular advancement device (MAD) and clonidine. The NNT (+/-95% CI) and ES were 2.2 (1.4 to 5.3) and 1.5 for the MAD, and 3.2 (1.7 to 37.3) and 0.9 for clonidine, respectively. An NNT of 3.8 (1.9 to -69.4) and an ES of 0.6 were observed with the occlusal splint, with a reduction of 42% in the SB index. NNT could not be calculated for clonazepam, although the ES was 0.9. CONCLUSION: Although the NNT and ES results seem to indicate that the MAD and clonidine are the most promising experimental treatments, both treatments were associated with side effects (ie, discomfort for the MAD; REM suppression and morning hypotension for clonidine). The occlusal splint and clonazepam seem to be acceptable short-term alternatives, although further longitudinal, large sample size randomized controlled trials in SB management are needed.

The International Journal of Prosthodontics


Sleep bruxism is associated to micro-arousals and an increase in cadiac sympathetic activity

Sleep bruxism (SB) subjects show a higher incidence of rhythmic masticatory muscle activity (RMMA) than control subjects. RMMA is associated with sleep micro-arousals. This study aims to: (i) assess RMMA/SB episodes in relation to sleep cycles; (ii) establish if RMMA/SB and micro-arousals occur in relation to the slow wave activity (SWA) dynamics; (iii) analyze the association between RMMA/SB and autonomic cardiac activity across sleep cycles. Two nights of polygraphic recordings were made in three study groups (20 subjects each): moderate to high SB, low SB and control. RMMA episodes were considered to occur in clusters when several groups of RMMA or non-specific oromotor episodes were separated by less than 100 s. Correlations between sleep, RMMA/SB index and heart rate variability variables were assessed for the first four sleep cycles of each study group. Statistical analyses were done with SYSTAT and SPSS. It was observed that 75.8% of all RMMA/SB episodes occurred in clusters. Micro-arousal and SB indexes were highest during sleep cycles 2 and 3 (P < 0.001). Within each cycle, micro-arousal and RMMA/SB indexes showed an increase before each REM sleep (P <or= 0.02). The cross-correlation plot for micro-arousal index showed positive association from 4 min preceding SB onset in the moderate to high SB subjects (P <or= 0.06). The cross-correlation plot revealed that SWA decreases following SB onset (P <or= 0.05). Further cross-correlation analysis revealed that a shift in sympatho-vagal balance towards increased sympathetic activity started 8 min preceding SB onset (P <or= 0.03). In moderate to severe SB subjects, a clear increase in sympathetic activity precedes SB onset.


Quantitative analysis of surface EMG activity of cranial and leg muscles across sleep stages in human.

OBJECTIVE: The aim of this study was to make a quantitative analysis of the changes in cranial and limb muscle activity from wakefulness to light and deep sleep stages and during rapid eye movement (REM) sleep of normal subjects. METHODS: Polysomnographic recordings were made of the sleep of 9 healthy human subjects, including electromyograms of the suprahyoid, temporalis and masseter cranial muscles and the anterior tibialis limb muscle. Quantitative assessments of EMG activity were carried out with root mean square (RMS) and frequency-spectral analysis (FSA) methods. RESULTS: From wakefulness to sleep, a significant reduction (-25.2 to -71.2%; P < 0.01) was observed in EMG activity (for both RMS and FSA) of the 3 cranial muscles using both methods of analysis. The EMG activity of suprahyoid muscle further decreased from non-REM to REM sleep (-17.8 to -43.0%; P < 0.01). In contrast, the EMG activity of the anterior tibialis muscle was only slightly reduced across sleep stages and did not further reduce during REM sleep. During REM sleep, all the 4 muscles maintained minimal activity. CONCLUSIONS: The maintenance of muscle activity during REM sleep suggests that a minimal level of activity is required to preserve physiological functions (e.g. airway patency, posture) related to homeostasis and bodily protection. SIGNIFICANCE: This study suggests that quantitative sleep EMG analysis is important for understanding the mechanisms of sleep-related movement disorders or when objective assessment of changes in EMG activity are needed for diagnostic purposes or for the assessment of drug efficiency.


The Multi-telemetering Measurement and Analysis of Sleep Associated Bruxism

マルチテレメータシステムを用いた睡眠時ブラキシズムの測定と解析

The Journal of the Japan Prosthodontic Society


Analysis of biological signals during sleep associated bruxism

睡眠時ブラキシズム発現に伴う生体信号の解析

The Journal of Japanese Society of Stomatognathic Function


口腔顔面痛に対するボツリヌス毒素効果メカニズム

口腔顔面痛に対するボツリヌス毒素効果メカニズム


睡眠時ブラキシズムの簡便な診断法の確立と対処法の検討

睡眠時ブラキシズムの簡便な診断法の確立と対処法の検討


Development of Prototype Jaw Operated Alternative Computer Mouse

下顎の動きで操作する代替コンピュータマウスの試作


睡眠時ブラキシズム中の顎運動様式

睡眠時ブラキシズム中の顎運動様式


Study on Analysis of Jaw Movements during Nocturnal Bruxism Event

睡眠時ブラキシズム発現に伴う顎運動の解析法の検討

日本補綴歯科学会誌. 特別号, 社団法人日本補綴歯科学会学術大会プログラム・抄録集 = Program and abstracts, the ... scientific meeting of Japan Prosthodontic Society


The Relationship between Jaw Movement and Masseter Muscle EMG during Sleep Associated Bruxism


睡眠時ブラキシズムの咬筋活動と顎運動

睡眠時ブラキシズムの咬筋活動と顎運動