Bruxism in Movement Disorders: A Comprehensive Review

Prevalence, awareness, and management of bruxism in Thai dental students: A cross-sectional study

OBJECTIVE

To determine the prevalence of self-reported bruxism, awareness of bruxism's adverse effects, and bruxism management among Thai undergraduate dental students.

METHODS

An online self-reported questionnaire was designed and tested for validity and reliability and then distributed to dental students at 12 universities in Thailand from September 2020 to January 2021.

RESULTS

There were 464 respondents (338 females and 126 males) with an average age of 21.42 ± 2.06 years. The prevalence of self-reported awake and sleep bruxism was 35.78% and 37.28%, respectively, and 19.40% had both awake and sleep bruxism. Awareness scores were higher for dentists than for patients (p< 0.001). Only 12.14% of sleep bruxers still wear an occlusal splint for bruxism management.

CONCLUSION

The prevalence of self-reported awake and sleep bruxism was high among Thai dental students. They are well aware of the adverse effects of bruxism with inappropriate management of the condition.

The relationship between possible, probable, or definite sleep bruxism and sleep quality: A systematic review

It has been suggested that sleep bruxism may interrupt sleep continuity, hence potentially influencing sleep quality. The aim of this study was to systematically review the relationship between possible, probable, and definite sleep bruxism and sleep quality in otherwise healthy individuals. A systematic search on sleep bruxism and sleep quality was performed in seven databases until 19 December 2022. Eligible articles were screened, and quality assessment was performed via the Joanna Briggs Institute Scale. Of 3681 articles screened, 13 were included in this study. Of these, six evaluated the relationship between sleep quality and possible sleep bruxism, three with probable sleep bruxism, and four with definite sleep bruxism. An association between poor sleep quality and sleep bruxism was found among those individuals diagnosed with possible and probable sleep bruxism. However, the studies conducted in individuals with definite sleep bruxism failed to demonstrate any association. With more reliable measures to evaluate sleep bruxism, a relationship between sleep bruxism and sleep quality was not evident.

Biomechanical effects of different materials for an occlusal device on implant-supported rehabilitation in a tooth clenching situation: A 3D finite element analysis

PURPOSE

The purpose of this 3D finite element analysis was to evaluate the biomechanical effects of different materials used to fabricate occlusal devices to achieve stress distribution in simulated abutment screws, dental implants, and peri-implant bone tissue in individuals who clench their teeth.

MATERIALS AND METHODS

Eight 3D models simulated a posterior maxillary bone block with three external hexagon implants (Ø4.0 × 7.0 mm) supporting a 3-unit screw-retained metal-ceramic prosthesis with different crown connection (splinting), and the use of an occlusal device (OD). The OD was modeled to be 2-mm thick. ANSYS 19.2 software was used to generate the finite-element models in the pre-and post-processing phases. Simulated abutment screws and dental implants were evaluated by von Mises stress maps, and simulated bone was evaluated by maximum principal stress and microstrain maps by using a finite element software program.

RESULTS

The highest stress values in the dental implants and screws were observed in single crowns without OD (M1). Furthermore, the highest stress values and bone tissue strain were found in single crowns without OD (M1). The simulated material for the OD did not cause many discrepancies in terms of the stress magnitude in the simulated dental implant and abutment screw for both single and splinted crowns; however, more rigid materials exhibited lower stress values.

CONCLUSION

The use of OD was effective in reducing stress in the simulated implants and abutment screws and stress and strain in the simulated bone tissue. The material used to simulate the OD influenced the biomechanical behavior of implant-supported fixed prostheses, whereas splints with rigid materials such as PEEK and PMMA exhibited better biomechanical behavior.

The use of botulinum toxin for grinding in patients with Rett syndrome-Case report

AIMS

Rett syndrome (RTT) is a neurodevelopmental disorder caused by a mutation in the methyl-CpG-binding protein 2 (MECP2) gene. It is characterized by profound and severe motor disability. Patients with RTT grind their teeth, causing damage to their permanent teeth. This article aims to describe the case of an 8-year-old child with RTT and the methods of botulinum toxin-based treatment for teeth grinding.

METHODS AND RESULTS

Surface electromyography (sEMG) was used to monitor the effects of treatment. The masseter and temporal muscles, responsible for the elevation of the mandible, were injected with botulinum toxin. The results of the sEMG examination performed 1 week, 1 month and 4 months after toxin administration were compared to the sEMG conducted before treatment. The research demonstrates a significant reduction in both grinding frequency and tension of the masseter and temporal muscles.

CONCLUSION

Possible adverse effects after chronic use of botulinum toxin were discussed. The article also emphasizes the need for masticatory muscle rehabilitation during botulinum toxin therapy. However, it is necessary to repeat this procedure on a larger group of children with RTT to establish our efforts' efficacy.

Sleep bruxism: The past, the present, and the future-evolution of a concept

BACKGROUND

The concept of sleep bruxism (SB) has evolved exponentially over the past several decades. Many theories and hypotheses have been proposed as to the definition, pathophysiology, and management of SB, from the early 1960s through the present. The role of peripheral factors, such as dental occlusion, in the pathogenesis of SB has been discarded.

TYPES OF STUDIES REVIEWED

The authors searched several electronic databases (ie, PubMed, Google Scholar, Web of Science, Embase, and Ovid MEDLINE) for studies on bruxism. The search was conducted from January 1961 through May 2023 and yielded 4,612 articles, of which 312 were selected for comprehensive review after eliminating duplicates and nonfocused articles.

RESULTS

There has been an evident progressive shift from the role of peripheral factors, such as dental occlusion, to more central factors, such as the involvement of a central pattern generator as well as the autonomic nervous system, in the genesis of bruxing movements. There is continued robust interest in the dental community to elucidate the contributing factors involved in SB.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The neurophysiology of SB appears to be leaning more toward central rather than peripheral factors. There is increasing evidence of the role of the autonomic nervous system, genetics, and comorbidities in the genesis of SB. The scientific literature seems to refute the role of dental occlusion in the causation of bruxing movements. As per the literature, there has been a paradigm shift in the definition and genesis of SB and its possible dental implications and management, which also highlights the need for succinct scientific studies in this regard.

Evaluation of mandibular motion in adolescents with skeletal class II division 1 malocclusion during mandibular advancement using clear functional aligners: a prospective study

BACKGROUND

This study aimed to evaluate the characteristics of mandibular protrusive condylar trajectory in adolescents with skeletal Class II Division 1 malocclusion and the changes of condylar trajectory during mandibular advancement (MA) treatment using clear functional aligners.

METHODS

This prospective study consisted of a cross-sectional study and a longitudinal study. In cross-sectional study, sixty-one adolescents were divided into two groups: Class I (n = 30) and Class II Division 1 (n = 31). The condylar trajectory was measured and compared using the Mann-Whitney U test. The longitudinal study was the MA treatment group using clear functional aligner and consisted of 16 participants from Class II Division 1group. The condylar trajectory was collected at three-time points: pre-treatment (T1), during MA treatment at approximately 3 months (T2, 105.6 days average), and at the end of MA treatment (T3, 237.6 days average). The changes at T1, T2, and T3, as well as the symmetry between the left and right condyles across all groups, were examined using the Wilcoxon paired test.

RESULTS

A greater increase in the anteroposterior displacement and space displacement during protrusive movements was observed in the Class II Division 1 group compared with that in the Class I group, with a large difference being observed in the left and right condylar movements. The condylar anteroposterior displacement and space displacement decreased significantly at T2 and increased significantly at T3; however, no significant difference was observed between T1 and T3. A significant difference was observed between the condylar movement on the left and right sides at T1; however, no significant difference was observed at T2 and T3.

CONCLUSIONS

Adolescents with Class II Division 1 malocclusion had higher protrusive capacity than those with Class I. Moreover, their left and right condylar motion was more asymmetric. The range of condyle motion decreased first and then increased during MA therapy, and the left and right condyle movement became more symmetrical, which may be the adaptive response of neuromuscular function to the changes in jaw position.

Neurodevelopmental disorders as a risk factor for temporomandibular disorder: evidence from Mendelian randomization studies

Objective: This study aims to clarify the incidence rate of temporomandibular joint disease in patients with mental disorders. Methods: Data extracted from the Psychiatric Genomics Consortium and FinnGen databases employed the Mendelian Randomization (MR) method to assess the associations of three neurodevelopmental disorders (NDDs)-Attention-Deficit/Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD), and Tourette's Disorder (TD)-as exposure factors with Temporomandibular Disorder (TMD). The analysis used a two-sample MR design, employing the Inverse Variance Weighted (IVW) method to evaluate the relationships between these disorders and Temporomandibular Disorder. Sensitivity analysis and heterogeneity assessments were conducted. Potential confounding factors like low birth weight, childhood obesity, and body mass index were controlled for. Results: The study found that ADHD significantly increased the risks for TMD (OR = 1.2342, 95%CI (1.1448-1.3307), p < 0.00001), TMD (including avohilmo) (OR = 1.1244, 95%CI (1.0643-1.1880), p = 0.00003), TMD-related pain (OR = 1.1590, 95%CI (1.0964-1.2252), p < 0.00001), and TMD-related muscular pain associated with fibromyalgia (OR = 1.1815, 95%CI (1.1133-1.2538), p < 0.00001), while other disorders did not show significant causal relationships. Conclusion: This study reveals the elevated risk of various TMD aspects due to ADHD. Furthermore, we discuss the link between low vitamin D levels ADHD and TMD. Future research should address these limitations and delve further into the complex interactions between ADHD, ASD, TD, and TMD.

Risk of sleep problems in a clinical sample of children who stutter

PURPOSE

Previous studies have shown increased prevalence of sleep problems among people who stutter. However, there is a lack of knowledge about what these sleep problems may specifically be.

METHOD

Fifty children who stutter (CWS) from 6;0 to 12;9 years of age and 50 age- and gender-matched controls participated in this study. Parents did not report coexisting conditions, excepting stuttering and/or sleep problems. Sleep problems were investigated using a standardized questionnaire answered by parents. The questionnaire shows cut-off scores to identify the risk of sleep problems as a whole and on each one of the six subscales (i.e., disorders of initiating and maintaining sleep; sleep breathing disorders; disorders of arousal; sleep-wake transition disorders; disorders of excessive somnolence; and sleep hyperhidrosis). Scores above the cut-off are suggestive of sleep problems.

RESULTS

Twenty-one CWS scored higher than the cut-off on the sleep questionnaire compared to only two controls (p < 0.00001). Specifically, CWS scored higher than controls in disorders of initiating and maintaining sleep, sleep-wake transition disorders (especially jerking, sleep talking, and bruxism), and disorders of excessive somnolence (p < 0.0083, corrected for multiple comparisons).

DISCUSSION

Compared to controls, CWS are at greater risk for sleep problems, which are not consequences of coexisting disorders. Present findings confirm and expand current knowledge about sleep problems in CWS. Directionality possibilities and clinical implications are discussed.

Occurrence, presence and severity of bruxism and its association with altered state of consciousness in individuals with severe acquired brain injury

BACKGROUND

Excessive jaw muscle activity is a frequent complication after acquired brain injury (ABI).

OBJECTIVE

The study aimed to identify the occurrence and severity of jaw muscle activity and its association with altered state of consciousness in patients with ABI.

METHODS

A total of 14 severe ABI patients with varied altered state of consciousness were recruited. A single-channel electromyographic (EMG) device was used to assess the jaw muscle activity for three consecutive nights during Week 1 and Week 4 following admission. Differences in number of EMG episodes/h between Week 1 and 4 were analysed using non-parametric tests and association between the EMG activity and altered state of consciousness were analysed using Spearman's correlation test.

RESULTS

Nine of fourteen (64%) patients showed indications of bruxism (cutoff: >15 EMG episodes/h). The average EMG episodes/h at admission were 44.5 ± 13.6 with no significant changes after Week 4 of admission (43 ± 12.9; p = .917). The EMG episodes/h ranged from 2 to 184 during Week 1 and 4-154 during Week 4. There were no significant correlations between the number of EMG episodes/h during the three nights and the individuals altered state of consciousness during Week 1 and Week 4.

CONCLUSION

Patients with ABI had a conspicuously high but variable level of jaw muscle activity at admission and it tend to remain high after 4 week of hospitalisation which could potentially lead to adverse effects such as excessive tooth wear, headaches and pain in jaw muscles. The lack of associations between individuals altered level of consciousness and EMG activity could be due to low sample size and further studies are clearly warranted in this patient group with special needs. Single-channel EMG devices can record jaw muscle activity early in the hospitalisation period and might be a helpful tools for early detection of bruxism in ABI patients.

Bruxism and oro-facial pain not related to temporomandibular disorder conditions: Comorbidities or risk factors?

INTRODUCTION

Bruxism has historically been of particular interest to the field of dentistry, primarily due to the inferred damage it may cause to the dentition and supporting periodontal structures. The definition of bruxism itself has undergone multiple changes over time. In addition, the effects of bruxism as it relates to oro-facial pain conditions has remained a debatable topic.

PURPOSE

To review the available literature relating to bruxism and non-temporomandibular disorder (TMD) pain conditions.

METHODS

A literature search was conducted with the assistance of an expert librarian. The following databases were reviewed: PubMed, MEDLINE, EMBASE and Google Scholar. For additional references, articles were also retrieved by hand search from the selected papers. Any articles that were not published in English, or the focus were related to temporomandibular disorders were excluded.

CONCLUSIONS

While bruxism and certain headache conditions do tend to occur together frequently, evidence relating to any clear common pathophysiological mechanism has yet to be fully elucidated. Robust evidence as it relates to the relationship between bruxism and other non-TMD oro-facial pains is also lacking.

Secondary bruxism: A valid diagnosis or just a coincidental finding of additional masticatory muscle activity? A narrative review of literature

INTRODUCTION

Bruxism is defined as a repetitive masticatory muscle activity that can manifest it upon awakening (awake bruxism-AB) or during sleep (sleep bruxism-SB). Some forms of both, AB and SB can be associated to many other coexistent factors, considered of risk for the initiation and maintenance of the bruxism. Although controversial, the term 'secondary bruxism' has frequently been used to label these cases. The absence of an adequate definition of bruxism, the non-distinction between the circadian manifestations and the report of many different measurement techniques, however, are important factors to be considered when judging the literature findings. The use (and abuse) of drugs, caffeine, nicotine, alcohol and psychoactive substances, the presence of respiratory disorders during sleep, gastroesophageal reflux disorders and movement, neurological and psychiatric disorders are among these factors. The scarcity of controlled studies and the complexity and interactions among all aforementioned factors, unfortunately, does not allow to establish any causality or temporal association with SB and AB. The supposition that variables are related depends on different parameters, not clearly demonstrated in the available studies.

OBJECTIVES

This narrative review aims at providing oral health care professionals with an update on the co-risk factors and disorders possibly associated with bruxism. In addition, the authors discuss the appropriateness of the term 'secondary bruxism' as a valid diagnostic category based on the available evidence.

CONCLUSION

The absence of an adequate definition of bruxism, the non-distinction between the circadian manifestations and the report of many different measurement techniques found in many studies preclude any solid and convincing conclusion on the existence of the 'secondary' bruxism.

Advancements in Methods of Classification and Measurement Used to Assess Tooth Mobility: A Narrative Review

Evaluating tooth mobility is clinically significant, not only for diagnosing periodontal tissues but also in determining the overall periodontal treatment plan. Numerous studies related to tooth mobility have been conducted over the years, including the proposal of various classifications as well as the development of electronic devices for objective measurement. However, there is still no consensus on the measurement methods and criteria for assessing tooth mobility. In this study, we provide a comprehensive review of past and current tooth mobility classification and measurement methods. In order to propose a new method to intuitively evaluate tooth mobility based on previous studies, a digital approach capable of recording tooth micromovements induced by dynamic load should be considered.

Nutrient insufficiencies and deficiencies involved in the pathogenesis of bruxism (Review)

Stress has been well-documented to have a significant role in the etiopathogenesis of bruxism. Activation of the hypothalamic-pituitary-adrenal axis (HPA) and subsequent release of corticosteroids lead to increased muscle activity. Neurological studies have demonstrated that chronic stress exposure induces neurodegeneration of important neuronal structures and destabilization of the mesocortical dopaminergic pathway. These disruptions impair the abilities to counteract the overactivity of the HPA axis and disinhibit involuntary muscle activity, while at the same time, there is activation of the amygdala. Recent evidence shows that overactivation of the amygdala under stressful stimuli causes rhythmic jaw muscle activity by over activating the mesencephalic and motor trigeminal nuclei. The present review aimed to discuss the negative effects of certain vitamin and mineral deficiencies, such as vitamin D, magnesium, and omega-3 fatty acids, on the central nervous system. It provides evidence on how such insufficiencies may increase stress sensitivity and neuromuscular excitability and thereby reduce the ability to effectively respond to the overactivation of the sympathetic nervous system, and also how stress can in turn lead to these insufficiencies. Finally, the positive effects of individualized supplementation are discussed in the context of diminishing anxiety and oxidative stress, neuroprotection and in the reversal of neurodegeneration, and also in alleviating/reducing neuromuscular symptoms.

The prevalence of bruxism and oral parafunction activities among Israeli juveniles with autism spectrum disorder: A preliminary study during the COVID-19 pandemic

OBJECTIVE

To evaluate the prevalence of oral habits, bruxism, and Temporomandibular Disorders (TMD) injuvenileswithautisticspectrumdisorder(ASD).

METHODS

Data included 165 juveniles diagnosed with ASD, allocated to younger group aged 6 21 (n=86) and older group aged 13-21 (n=79).

RESULTS

Sleep bruxism was reported by 26.7% in the younger group and by 5% in the older group. Awake bruxism was reported by 22% and 17.7%, respectively. Oral habits were reported by 43% of all participants, with similar rate in both groups. TMD related p ain was low in both groups (6.3% and 7% respectively). The influence of the COVID 19 pandemic on oral parafunction was moderate in the younger group (17.4%) and mild in the older group (8.6%), influence on bruxism was mild in both groups (5.8% and 2.5%, respectively).

CONCLUSION

The prevalence of bruxism and oral parafunctions was similar to the reported in the literature for the general population.

From parasomnia to agrypnia excitata - An illustrative case on diagnostic approach

The diagnostic approach to sleep-related movements disorders is seldom discussed. We report a case of fatal familial insomnia who initially presented with persistent limb movements in sleep, which later progressed to a state of agrypnia excitata. Here, the evaluation of abnormal movements in sleep is discussed using a step-by-step diagnostic approach. Although no cure is available for fatal familial insomnia, prompt recognition of this condition is important to facilitate proper management, including the involvement of interdisciplinary neuropalliative care.

Associations between Bruxism, Stress, and Manifestations of Temporomandibular Disorder in Young Students

Bruxism is a repetitive activity of the masticatory muscles, which determine teeth grinding or clenching, associated with rigidity, bracing, or thrusting of the mandibula. The aim of this study was to determine the prevalence of possible bruxism in 328 students attending the Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, and its associations with stress and other manifestations of the temporo-mandibular disorder. This was a questionnaire-based study to collect information on self-evaluation of bruxism presence, frequency of specific episodes, stress, anxiety, and other manifestations of temporo-mandibular disorder. Self-evaluated bruxism was identified in 39.33% from the entire study group, allowing us to define two subgroups for further analysis. Sleep bruxism was present in 16.28% of participants; awake bruxism was present in 68.99%, while 14.73% of participants presented a combined form. The main manifestation of bruxism was reported as teeth grinding. Fatigue was identified as a common clinical sign of bruxism and temporo-mandibular disorder. Group distribution analysis (Chi-Square) indicated significant associations between bruxism and stress, panic, restlessness, or increased stress during the COVID-19 pandemic (p < 0.05). Bruxism, and especially awake bruxism, has increased in prevalence among young students, and it has been associated with increased levels of stress.

Parkinson's disease, temporomandibular disorder pain and bruxism and its clinical consequences: a protocol of a single-centre observational outpatient study

INTRODUCTION

A recent questionnaire-based study suggested that bruxism and painful temporomandibular disorders (TMD pain) may be more prevalent in patients with Parkinson's disease (PD) compared with controls. The presence of both bruxism and TMD pain may negatively influence patients' quality of life. The present study is designed to clinically and more objectively investigate the presence of bruxism and TMD pain in patients with PD. The secondary aim of the study is to identify factors associated with bruxism and TMD pain in patients with PD, such as disease severity and dopaminergic medication usage. Furthermore, the presence of tooth wear in patients with PD will be studied as this can be a major consequence of bruxism. Finally, deviations in saliva composition that may contribute to tooth wear will be studied.

METHODS AND ANALYSIS

This is a single-centre observational outpatient study at the Amsterdam University Medical Centres, location VUmc. All patients with a clinical diagnosis of PD will be eligible for inclusion. Participants will fill in a set of questionnaires. Subsequently, patients will be examined clinically for, among others, TMD pain, presence and severity of tooth wear, and deviations in saliva composition. Sleep-time registrations will take place for 5 nights with the GrindCare GC4 (ie, a portable, single-channel electromyographic recorder) to assess sleep bruxism and simultaneously by the use of the BruxApp for 5 days to assess awake bruxism. We will partly use data collected during standard clinical care to minimise patient burden.

ETHICS AND DISSEMINATION

The scientific and ethical aspects of this study protocol have been approved by the Medical Ethics Review Committee of the Amsterdam UMC, location VUmc; NL. 2019.143. Informed consent will be obtained from all participants. The results will be published in a peer-reviewed journal, if relevant presented at conferences, and published as part of a PhD thesis.

TRIAL REGISTRATION NUMBER

NL8307.

The dental demolition derby: bruxism and its impact - part 1: background

Bruxism may lead to changes or damage to the oral and perioral tissues. Bruxism may occur during sleep or when awake. Many patients will not require active management; however, for some, intervention is required. Control of bruxism may be difficult, if not impossible, but the need exists for preservation of the dentition and quality of life. A prediction of risk to the tissues for the planning of interventions is difficult and relies upon evidence of past damage and assessment of future risks. Treatment options may need to be imaginative and rescuable. This series of papers will review the aetiology of bruxism, its impacts and treatment strategies for persistent bruxers who are at risk of, or suffering, tissue damage.

Movement disorders in patients with Rett syndrome: A systematic review of evidence and associated clinical considerations

AIM

This systematic review identified and thematically appraised clinical evidence of movement disorders in patients with Rett syndrome (RTT).

METHOD

Using PRISMA criteria, six electronic databases were searched from inception to April 2021. A thematic analysis was then undertaken on the extracted data to identify potential themes.

RESULTS

Following the thematic analysis, six themes emerged: (i) clinical features of abnormal movement behaviors; (ii) mutational profile and its impact on movement disorders; (iii) symptoms and stressors that impact on movement disorders; (iv) possible underlying neurobiological mechanisms; (v) quality of life and movement disorders; and (vi) treatment of movement disorders. Current guidelines for managing movement disorders in general were then reviewed to provide possible treatment recommendations for RTT.

CONCLUSION

Our study offers an enriched data set for clinical investigations and treatment of fine and gross motor issues in RTT. A detailed understanding of genotype-phenotype relationships of movement disorders allows for more robust genetic counseling for families but can also assist healthcare professionals in terms of monitoring disease progression in RTT. The synthesis also showed that environmental enrichment would be beneficial for improving some aspects of movement disorders. The cerebellum, basal ganglia, alongside dysregulation of the cortico-basal ganglia-thalamo-cortical loop, are likely anatomical targets. A review of treatments for movement disorders also helped to provide recommendations for treating and managing movement disorders in patients with RTT.

Association between sleep and awake bruxism in patients with migraine

IntroductionWhen migraine undergoes transformation from episodic to chronic form it becomes more disabling due to the refractoriness in treatment and the emergence of comorbidities, with the establishment of a bidirectional relationship between sleep bruxism and chronic migraine. This study aimed to assess whether sleep and awake bruxism are more prevalent in chronic migraine when compared to episodic migraine and also to establish possible clinical correlations with the process of chronification.Methods210 patients were allocated to the study, 97 with episodic migraine and 113 with chronic migraine, who underwent face-to-face interviews with the completion of the scales: specific questionnaire for the diagnosis of sleep and awake bruxism, PHQ-9 (depression), GAD-7 (anxiety), Epworth Scale (daytime sleepiness), MIDAS (migraine incapacity) and HIT-6 (impact of headache). ResultsThe prevalence of sleep and awake bruxism was similar in patients with episodic versus chronic migraine (p = 0.300 and p = 0.238). The correlation of patients with concomitant awake and sleep bruxism and with high scores on the migraine incapacity (MIDAS) and headache impact (HIT-6) scales was higher among patients with chronic migraine than in patients with episodic migraine. (p <0.001 and p <0.001). ConclusionSleep and awake bruxism alone are not more prevalent in chronic migraine when compared to episodic migraine, although bruxism causes greater impact and disability on individuals with chronic migraine.

Oral Health Disorders in Parkinson's Disease: More than Meets the Eye

Despite clinical evidence of poor oral health and hygiene in Parkinson’s disease (PD) patients, the mouth is often overlooked by both patients and the medical community, who generally focus on motor or psychiatric disorders considered more burdensome. Yet, oral health is in a two-way relationship with overall health—a weakened status triggering a decline in the quality of life. Here, we aim at giving a comprehensive overview of oral health disorders in PD, while identifying their etiologies and consequences. The physical (abnormal posture, muscle tone, tremor, and dyskinesia), behavioral (cognitive and neuropsychiatric disorders), and iatrogenic patterns associated with PD have an overall detrimental effect on patients’ oral health, putting them at risk for other disorders (infections, aspiration, pain, malnutrition), reducing their quality of life and increasing their isolation (anxiety, depression, communication issues). Interdisciplinary cooperation for prevention, management and follow-up strategies need to be implemented at an early stage to maintain and improve patients’ overall comfort and condition. Recommendations for practice, including (non-)pharmacological management strategies are discussed, with an emphasis on the neurologists’ role. Of interest, the oral cavity may become a valuable tool for diagnosis and prognosis in the near future (biomarkers). This overlooked but critical issue requires further attention and interdisciplinary research.

Bruxism in Acute Neurologic Illness

PURPOSE OF REVIEW

While traditionally encountered in ambulatory settings, bruxism occurs in patients with a variety of acute neurologic illnesses including encephalitis, intracerebral hemorrhage, traumatic brain injury, hypoxic-ischemic encephalopathy, and acute ischemic stroke. Untreated bruxism in acute neurologic illness can lead to tooth loss, difficulty in mouth care resulting in recurrent aspiration pneumonia, endotracheal tube dislodgement, and even tongue laceration or amputation. Inpatient clinicians should be aware of the etiologies and management strategies for bruxism secondary to acute neurologic illness.

RECENT FINDINGS

Management strategies for bruxism are varied and include pharmacologic and non-pharmacologic therapies in addition to onabotulinumtoxinA (BoNT-A). Bruxism impacts patients with a variety of acute neurologic illnesses, and emerging evidence suggests successful and safe treatment strategies.

Associations among masticatory muscle activity, physical activity and self-reported oral behaviours in adult women

OBJECTIVES

To examine the relationship between masticatory muscle activity (MMA), self-reported oral behaviours (OBs) and overall physical activity (PA) in adult women.

MATERIALS AND METHODS

MMA and PA were assessed by a wearable electromyography (EMG) device and accelerometer respectively, worn over 2 non-consecutive days by 53 women (mean age 27.5 ± 6.4 years). Following the second recording day, self-reported OBs were assessed. MMA was assessed by the number, amplitude and duration of masseter contraction episodes. Masseter muscle EMG outcome measures were number of contraction episodes per hour (CEs/h) and the relative contraction time (RCT%). PA was assessed by time accumulated in moderate to vigorous physical activity (MVPA) and 10-min bouts of MVPA per hour. Data were analysed using mixed model analysis.

RESULTS

MMA in free-living conditions consisted mostly of low-amplitude (<10% maximum voluntary clenching) and short-duration (<10 s) contraction episodes. Masseter CEs/h were not associated with self-reported levels of OB. Masseter CEs/h were positively associated with time accumulated in MVPA (F = 9.9; p = 0.002) and negatively associated with 10-min bouts of MVPA/h (F = 15.8; p <0.001). RCT% was not significantly associated with either.

CONCLUSIONS

Objectively assessed MMA is not associated with self-reported OB in free-moving adult females. Moderate to vigorous exercise and physical inactivity are accompanied with an increase in the number of masseter muscle contractions and thus possibly tooth clenching activity.

CLINICAL RELEVANCE

OB can be influenced by the type and extent of PA. Subjective assessment of MMA by questionnaire and/or interviews may be invalid.

Botulinum Toxin in Movement Disorders: An Update

Since its initial approval in 1989 by the US Food and Drug Administration for the treatment of blepharospasm and other facial spasms, botulinum toxin (BoNT) has evolved into a therapeutic modality for a variety of neurological and non-neurological disorders. With respect to neurologic movement disorders, BoNT has been reported to be effective for the treatment of dystonia, bruxism, tremors, tics, myoclonus, restless legs syndrome, tardive dyskinesia, and a variety of symptoms associated with Parkinson's disease. More recently, research with BoNT has expanded beyond its use as a powerful muscle relaxant and a peripherally active drug to its potential central nervous system applications in the treatment of neurodegenerative disorders. Although BoNT is the most potent biologic toxin, when it is administered by knowledgeable and experienced clinicians, it is one of the safest therapeutic agents in clinical use. The primary aim of this article is to provide an update on recent advances in BoNT research with a focus on novel applications in the treatment of movement disorders. This comprehensive review of the literature provides a critical review of evidence-based clinical trials and highlights recent innovative pilot studies.

Self-reported sleep bruxism is associated with vitamin D deficiency and low dietary calcium intake: a case-control study

Background

Sleep bruxism may result in deleterious effects including loss of tooth enamel, fracture of teeth or restorations, teeth hypersensitivity or pain, and headache. The aim was to study the link between sleep bruxism, low serum vitamin D, low consumption of dietary calcium, psychological symptoms, and frequent headache.

Methods

This case-controlled study included 50 individuals with sleep bruxism and 50 age and gender matched controls. 25-hydroxyvitamin D was measured in serum. Hospital Anxiety and Depression Scale was used to measure anxiety and depression. Data about dietary calcium and frequent headache were self-reported.

Results

Participants with sleep bruxism had lower 25-hydroxyvitamin D and higher scores of anxiety and depression compared to controls (p < 0.05). Vitamin D deficiency, abnormal scores of anxiety and depression, low calcium consumption (< 323 mg/day), and frequent headache were reported in higher % of individuals with sleep bruxism compared to controls (p < 0.05). Binary logistic regression showed that sleep bruxism was significantly associated with vitamin D deficiency (OR = 6.66, p = 0.02), low consumption of dietary calcium (OR = 5.94, p = 0.01), and frequent headache (OR = 9.24, p < 0.001). Multiple linear regression showed that anxiety was significantly associated with decreased 25-hydroxyvitamin D (p = 0.03), increased scores of depression (p < 0.001) and female sex (p = 0.01). Binary logistic regression also showed that frequent headache was significantly associated with sleep bruxism (OR = 5.51, p < 0.01).

Conclusions

Sleep bruxism was associated with vitamin D deficiency and low consumption of calcium and was also associated with increased scores of anxiety and depression. Further investigations should be performed to check if vitamin D and calcium supplementation could relieve sleep bruxism.

A comparative study between zirconia and titanium abutments on the stress distribution in parafunctional loading: A 3D finite element analysis

BACKGROUND

Zirconia has become a popular biomaterial in dental implant systems because of its biocompatible and aesthetic properties. However, this material is more fragile than titanium so its use is limited.

OBJECTIVES

The aim of this study was to compare the stresses on morse taper implant systems under parafunctional loading in different abutment materials using three-dimensional finite element analysis (3D FEA).

METHODS

Four different variations were modelled. The models were created according to abutment materials (zirconia or titanium) and loading (1000 MPa vertical or oblique on abutments). The placement of the implants (diameter, 5.0 × 15 mm) were mandibular right first molar.

RESULTS

In zirconia abutment models, von Mises stress (VMS) values of implants and abutments were decreased. Maximum and minimum principal stresses and VMS values increased in oblique loading. VMS values were highest in the connection level of the conical abutments in all models.

CONCLUSIONS

Using conical zirconia abutments decreases von Mises stress values in abutments and implants. However, these values may exceed the pathological limits in bruxism patients. Therefore, microfractures may be related to the level of the abutment.

Oral health status of children and adolescents with autism spectrum disorder: A systematic review of case-control studies and meta-analysis

Children and adolescents with autism spectrum disorder are thought to be more vulnerable to oral diseases than typically developing individuals due to cariogenic dietary habits, self-injurious behaviors, and increased barriers to dental care services. This review aimed to summarize current evidence comparing the oral health status of people diagnosed with and without autism spectrum disorder. Study selection and screening, data extraction, risk of bias assessment, and quality-of-evidence evaluation was conducted using the Grading of Recommendations Assessment Development and Evaluation approach and performed independently by two reviewers. A total of 16 studies were found eligible for qualitative synthesis and 15 were included in quantitative analysis. When comparing children and adolescents diagnosed with and without autism spectrum disorder, significantly higher prevalence of bruxism was identified. Individuals diagnosed with autism spectrum disorder were also found to have significantly lower salivary pH. However, no statistically significant differences in terms of caries prevalence and severity, oral hygiene and periodontal status, prevalence of malocclusion, dental traumatic injuries, as well as salivary flow rate and buffering capacity were found. The quality of evidence of each outcome was graded as very low mainly due to the overall high risk of bias, considerable heterogeneity, and imprecision.

Lay Abstract

Children and adolescents diagnosed with Autism Spectrum Disorder (ASD) are thought to be more vulnerable to oral diseases than typically-developing individuals. This is due to their increased barriers to dental care services, self-harm behaviors and dietary habits that may favor tooth decay. In this review, we summarized the current evidence comparing the oral health status of children and adolescents diagnosed with and without ASD. After a systematic search in the literature, we found that the salivary pH of individuals diagnosed with ASD was significantly lower, but the results were not clinically significant that can increase their risks to tooth decay. We also found weak evidence suggesting a higher percentage of children and adolescents diagnosed with ASD having the habit of tooth grinding compared with their neurotypical counterparts. When comparing salivary flow rate, tooth decay, gum diseases, tooth malalignment and tooth trauma; no significant differences were found between the two groups. The findings did not suggest ASD as a predisposing factor to oral diseases: other factors including sugary diet and inadequate oral hygiene may play a more important role. We also call for further research to establish more concrete association between ASD and oral diseases.

STXBP1 encephalopathy is associated with awake bruxism

Heterozygous mutations in syntaxin-binding protein 1 (STXBP1) gene are associated with early infantile epileptic encephalopathy 4 (EIEE4). This condition is characterized by epilepsy, developmental delay (DD), and various movement disorders. Herein, we will report 5 unrelated patients with different de novo mutations in STXBP1. In addition, we conducted an online survey through Facebook to identify the incidence of bruxism (BRX) in these patients. Four out of 5 patients (80%) presented with awake BRX (A-BRX). Bruxism was also reported in 81.4% (57/70) of the patients with STXBP1 encephalopathy through the online questionnaire. No consistent correlation was identified between the type of mutation and development of movement disorders or BRX. This is the first study to demonstrate A-BRX in patients with STXBP1 mutation. Given the role of STXBP1 in exocytosis of neurotransmitters and other manifestations of dopamine dysregulation in patients with STXBP1-EIEE4, we suggest that in patients with STXBP1 encephalopathy, A-BRX might be the result of the involvement of dopaminergic circuits.

Risk factors associated with reported bruxism among children and adolescents with Down Syndrome

Objective: Identify factors associated with the prevalence of reported bruxism in children/adolescents with Down Syndrome (DS). Methods: The study included 112 children/adolescents with DS and their parents/caregivers. Oral habits, pacifier/finger sucking, upper respiratory infections (<six months), and breathing type (nasal/buccal) were diagnosed. Reported bruxism was recorded through parents' report ("Does your child have audible teeth grinding?"). Results: Children/adolescents 8-12 years of age were 1.15 times more likely to belong to the group with reported bruxism (1.42-3.14). Children/adolescents 5-7 years of age were 3.38 times more likely to belong to the group with reported bruxism (1.26-9.03). Children/adolescents classified as mouth breathers were 2.87 times more likely to belong to the group with reported bruxism (1.18-6.98). Conclusion: Age and mouth breathing were associated with reported bruxism. Earlier interventions should be provided in order to limit and minimize possible damage that can affect childrens' quality of life.

Onabotulinum toxin-A injections for sleep bruxism: A double-blind, placebo-controlled study

OBJECTIVES

To test the safety and efficacy of onabotulinum toxin-A (BoNT-A) injections into the masseter and temporalis muscles in patients with symptomatic sleep bruxism.

METHODS

Participants 18 to 85 years old with clinically diagnosed sleep bruxism confirmed by polysomnography were enrolled in this randomized, placebo-controlled, 1:1, parallel-design trial with open-label extension. Participants were injected with BoNT-A 200 units (60 into each masseter and 40 into each temporalis) or placebo and were evaluated at 4 to 8 weeks after the initial treatment visit. The primary efficacy endpoint was clinical global impression (CGI), and the secondary efficacy endpoint was a visual analog scale (VAS) of change in bruxism and in pain at 4 to 8 weeks after injection. Exploratory endpoints included modified Montreal Bruxism Questionnaire, Headache Impact Test-6, total Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Self-Rated Anxiety Scale, and polysomnography data, including EMG recordings of the masseter and temporalis muscle bruxing events. Adverse events were recorded.

RESULTS

Thirty-one participants were recruited and 23 were randomized (19 female, age 47.4 ± 16.9 years). All 13 randomized to BoNT-A and 9 of 10 randomized to placebo completed the study. CGI (p < 0.05) and VAS of change (p < 0.05) favored the BoNT-A group. None of the exploratory endpoints changed significantly, but total sleep time and number/duration of bruxing episodes favored the BoNT-A group. Two participants randomized to BoNT-A reported a cosmetic change in their smile. No dysphagia or masticatory adverse events were reported.

CONCLUSIONS

BoNT-A effectively and safely improved sleep bruxism in this placebo-controlled pilot trial. A large multicenter trial is needed to confirm these encouraging data.

CLINICALTRIALSGOV IDENTIFIER

NTC00908050.

CLASS OF EVIDENCE

This study provides Class II evidence that botulinum injections into the masseter and temporalis muscles improve subjective bruxism and painful symptoms associated with sleep bruxism.

Botulinum toxin: State of the art

Botulinun neurotoxin (BoNT) has emerged as one of the most multipurpose therapeutic agents in modern medicine with more clinical applications than any other drug currently on the market. Initially developed in the treatment of strabismus and neurologic movement disorders, the use of botulinun neurotoxin has been expanding during the past 3 decades to include the treatment of a variety of ophthalmologic, gastrointestinal, urologic, orthopedic, dermatologic, dental, secretory, painful, cosmetic, and other conditions. In addition to onabotulinumtoxinA (Botox), abobotulinumtoxinA (Dysport), incobotulinumtoxinA (Xeomin), and RimabotulinumtoxinB (Myobloc or NeuroBloc) there are other novel botulinun neurotoxin products currently in development. With a better understanding of the cellular mechanisms of botulinun neurotoxin and advances in biotechnology, future botulinun neurotoxin products will likely be even more effective and customized to the specific indication and tailored to the needs of the patients. © 2017 International Parkinson and Movement Disorder Society.