Mood disorders in subjects with bruxing behavior

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.

Association between Psychological Distress and Possible, Probable, and Definite Sleep Bruxism-A Comparison of Approved Diagnostic Procedures

(1) Background: The relationship between sleep bruxism (SB) and psychological distress has been investigated in numerous studies and is heterogeneous. Different diagnostic procedures have been applied to determine SB. The aim of this study was to directly compare the association between psychological distress and SB diagnosed by different accepted methods. (2) Methods: Data of N = 45 subjects were analyzed, including group comparisons and correlation analyses. Following diagnostic methods for the determination of SB were used in one sample: self-report, clinical assessment, polysomnography with audio-video recording and a novel diagnostic sheet with analyzing software. Psychological distress was measured using the global severity index (GSI) of the Symptom Checklist-90-Standard (SCL-90-S). (3) Results: The GSI did not differ significantly between subjects with and without SB, regardless of the underlying diagnostic classification (p > 0.05). In-depth correlation analyses of self-report and clinical data revealed a weak-to-medium correlation with the GSI (r = 0.12-0.44). Due to non-normally distributed data, a test of statistical significance was not possible. Variables of instrumental methods such as the SB index (amount of SB activity per hour) of polysomnography (PSG) showed almost no correlation with psychological distress (r = -0.06-0.05). (4) Conclusions: Despite these limitations, the results provide an indication that the choice of diagnostic procedure may elucidate the variance in the correlation between SB and psychological distress.

Research routes on awake bruxism metrics: Implications of the updated bruxism definition and evaluation strategies

BACKGROUND

With time, due to the poor knowledge on it epidemiology, the need to focus on awake bruxism as a complement of sleep studies emerged.

OBJECTIVE

In line with a similar recent proposal for sleep bruxism (SB), defining clinically oriented research routes to implement knowledge on awake bruxism (AB) metrics is important for an enhanced comprehension of the full bruxism spectrum, that is better assessment and more efficient management.

METHODS

We summarised current strategies for AB assessment and proposed a research route for improving its metrics.

RESULTS

Most of the literature focuses on bruxism in general or SB in particular, whilst knowledge on AB is generally fragmental. Assessment can be based on non-instrumental or instrumental approaches. The former include self-report (questionnaires, oral history) and clinical examination, whilst the latter include electromyography (EMG) of jaw muscles during wakefulness as well as the technology-enhanced ecological momentary assesment (EMA). Phenotyping of different AB activities should be the target of a research task force. In the absence of available data on the frequency and intensity of wake-time bruxism-type masticatory muscle activity, any speculation about the identification of thresholds and criteria to identify bruxers is premature. Research routes in the field must focus on the improvement of data reliability and validity.

CONCLUSIONS

Probing deeper into the study of AB metrics is a fundamental step to assist clinicians in preventing and managing the putative consequences at the individual level. The present manuscript proposes some possible research routes to advance current knowledge. At different levels, instrumentally based and subject-based information must be gathered in a universally accepted standardised approach.

Altered electromyographic responses to emotional and pain information in awake bruxers: case-control study

OBJECTIVES

This study aims to investigate how emotional information and pain-related information affect the activity of the masticatory muscles in participants with awake bruxism and controls.

MATERIAL AND METHODS

Different videos and texts, with positive, negative, and neutral valence or related to pain, were presented to a sample of university students, while their electromyographic (EMG) activity around the masseter muscle and their skin conductance were recorded. Two groups were selected, with 24 subjects each: one group of subjects with definitive awake bruxism (confirmed by posterior EMG activity) who also suffered from moderate jaw discomfort, and another group of subjects without bruxism.

RESULTS

The results demonstrated that the subjects with definitive awake bruxism displayed greater muscular activity when presented videos and texts with negative valence, especially when related to pain, than the non-bruxist group.

CONCLUSIONS

This study supports the idea that persons with bruxism who also suffer moderate levels of jaw discomfort present greater bruxism activity when watching pain-related stimuli, and to a lesser extent when watching negative stimuli.

CLINICAL RELEVANCE

The increased muscular activity induced by negative and pain-related information might contribute to pain exacerbation and perpetuation in persons with bruxism who suffer from discomfort.

Childhood Trauma, Quality of Life, Sleep Quality, Anxiety and Depression Levels in People with Bruxism

Introduction

The aim was to investigate the relation between sociodemographic features, anxiety, depression, sleep quality, childhood trauma experiences, and quality of life and bruxism determining the risk factors in people with bruxism.

Methods

A total of 200 people were included in the study. Of the patients, 100 were diagnosed with bruxism and 100 were included in the control group. Sociodemographic Data Form, Hospital Anxiety Depression Scale (HAD), The Pittsburgh Sleep Quality Index (PSQI), Childhood Trauma Scale (CTS), Short Form-36 Quality of Life Scale (SF-36) were used.

Results

While there was no significant difference between the case group and the control group in terms of age, gender, marital status, and working status, there was a significant difference between educational levels. When the groups were compared a significant difference was found with regard to HAD-A (p<0.05), HAD-D (p<0.01), PSQI (p<0.01) and CTS (p<0.05) scores. While a significant difference was found when KF-36 subscales were examined, with regard to Physical Function (p<0.01), Pain (p<0.05), Social Function (p<0.05) and Mental Health (p<0.01) scores, no significant difference was detected between the subscales of Role Strength (p>0.05), General Health (p>0.05), Vital Energy (p>0.05) and Emotional Role (p>0.05). Regression analysis shows, (PSQI), HAD-D CTS scores predicted bruxism.

Conclusion

Higher depression scale scores, bad sleep quality, traumatic childhood experiences increase the risk for bruxism. Paying attention to the mental state of people diagnosed with bruxism in the treatment process and incorporating the psychiatrists in this process may increase the success rate of the treatment.

Personality traits and dental anxiety in self-reported bruxism. A cross-sectional study

OBJECTIVES

The aim of this study was to investigate the association between psychological factors (Personality and Dental anxiety) with self-reported bruxism-related symptoms.

METHODS

526 subjects, over 18 years old and not seeking dental treatment, were recruited from the families and acquaintances of dental students from the University of Salamanca. Bruxism activity was estimated by means of a six-item questionnaire aimed at recording common bruxism-related symptoms and clenching/grinding awareness. The Spanish version of the modified dental anxiety scale (MDAS) was used to determine the level of anxiety perceived in 5 typical scenarios of dental assistance. The NEO-FFI inventory was applied to assess personality profiles associated with 5 different factors (neuroticism, extroversion, openness, agreeableness, and conscientiousness). Pearson correlations, Student T-tests, and logistic regression modelling were used for the statistical analyses.

RESULTS

Thirty-five point nine percent of this adults sample was classified as being bruxers, where sleep bruxers comprised more than half of the sample at 20.2%. Bruxers tended to perceive more anxiety in all of the situations included within the MDAS, where they exhibited a higher level of phobia towards the teeth scaling and local anaesthetic injection. The risk of being considered a bruxer is reduced with age (OR: 0.99), and increases proportionally for some personality traits, such as neuroticism (OR: 1.06) and extraversion(OR: 1.04), to the MDAS total score (OR: 1.08) and in smokers (OR: 1.61), after controlling for all potentially confounding factors.

CONCLUSIONS

Self-reported bruxism is significantly associated to several personality traits (mainly neuroticism and extraversion) and to the level of dental anxiety (MDAS score).

CLINICAL SIGNIFICANCE

Clinicians should be aware of the typical psychological profiles of patients who experience bruxism and the relationship with dental phobias.

Signs of bruxism and temporomandibular disorders among patients with bipolar disorder

Background/Aim: There is an abundance of data regarding temporomandibular disorders (TMD) and bruxism specific to patients with bipolar disorder (BD). This study aimed to investigate the prevalence of TMD signs in subjects with and without BD. Material and Methods: The case group included 242 adult patients (103 men and 139 women) with BD and the control group included 187 subjects without BD (89 men and 98 women). The case and control groups were compared for the presence of bruxism and the signs of TMD including muscle and temporomandibular joint (TMJ) tenderness to palpation, limitation of maximum mouth opening, and TMJ sounds. Results: The frequency of at least one sign of TMD was significantly higher in patients with BD (191 ⁄242, 78.9%) than the control group (95 ⁄187, 50.8%) (p<0.001). Statistically significant differences were found between the case and control groups in terms of joint pain on palpation (p<0.05), masseter muscle pain on palpation (p<0.01), joint clicks (p<0.001) and limited mouth opening (p<0.001). Bruxism was significantly higher in patients with BD (49.6%) than the control group (19.8%) (p<0.001). Conclusions: Patients with BD appear to be more prone to having TMD signs and bruxism compared to the control group, but this comorbidity should be better understood by further studies.

Sleep-associated aspects of myofascial pain in the orofacial area among Temporomandibular Disorder patients and controls

STUDY OBJECTIVES

To assess sleep-associated aspects of temporomandibular disorder (TMD) with myofascial pain (MP) in the orofacial area of patients and controls.

MEASUREMENTS

Three hundred five female patients were screened to find 44 participants fulfilling the inclusion criteria, 22 suffering from MP and 22 in a control group. Sleep quality was assessed by use of the Pittsburgh Sleep-Quality-Index (PSQI) and a validated German sleep questionnaire (SF-AR). Tooth wear was assessed and anterior temporalis muscle activity was measured at home for several nights by use of a portable electromyography (EMG) device.

RESULTS

22 patients (45.0 ± 13.6 years) and 22 controls (45.2 ± 9.0 years) were recruited. The PSQI sum-score was 7.5 ± 3.7 for patients and 4.4 ± 3.0 for controls (p = 0.006). The SF-AR showed that 23% of the controls and 14% of the patients were "long sleepers". The overall number of episodes in the two groups was not significantly different (4.10 ± 2.65 versus 4.57 ± 1.99 episodes per hour). However, more patients had temporalis muscle activity possibly related to SB during all four consecutive nights (p = 0.04). According to the International Classification of Sleep Disorders - Third Edition (ICSD-3) criteria, 13.6% of the controls and 71.4% of the patients (p < 0.001) showed SB.

CONCLUSIONS

Sleep-associated disturbances, including reduction of sleep quality and greater prevalence of SB and facial pain in the morning, occurred significantly more often among TMD patients. Additionally, SB fluctuated over the nights especially in controls. This should be taken into consideration when the prevalence of SB is assessed by use of EMG.

Mood Spectrum Model: Evidence reconsidered in the light of DSM-5

AIM: to investigate studies conducted with the Mood Spectrum Structured Interviews and Self-Report versions (SCI-MOODS and MOODS-SR).

METHODS: We conducted a review of studies published between 1997 and August 2014. The search was performed using Pubmed and PsycINFO databases. Analysis of the papers followed the inclusion and exclusion criteria recommended by the PRISMA Guidelines, namely: (1) articles that presented a combination of at least two terms, “SCI-MOODS” [all fields] or “MOODS-SR” [all fields] or “mood spectrum” [all fields]; (2) manuscript in English; (3) original articles; and (4) prospective or retrospective original studies (analytical or descriptive), experimental or quasi-experimental studies. Exclusion criteria were: (1) other study designs (case reports, case series, and reviews); (2) non-original studies including editorials, book reviews and letters to the editor; and (3) studies not specifically designed and focused on SCI-MOODS or MOODS-SR.

RESULTS: The search retrieved 43 papers, including 5 reviews of literature or methodological papers, and 1 case report. After analyzing their titles and abstracts, according to the eligibility criteria, 6 were excluded and 37 were chosen and included. The SCI-MOODS and the MOODS-SR have been tested in published studies involving 52 different samples across 4 countries (Italy, United States, Spain and Japan). The proposed mood spectrum approach has demonstrated its usefulness mainly in 3 different areas: (1) Patients with the so-called “pure” unipolar depression that might manifest hypomanic atypical and/or sub-threshold aspects systematically detectable with the mood questionnaire; (2) Spectrum features not detected by other instruments are clinically relevant, because they might manifest in waves during the lifespan, sometimes together, sometimes alone, sometimes reaching the severity for a full-blown disorder, sometimes interfering with other mental disorders or complicating the course of somatic diseases; and (3) Higher scores on the MOODS-SR factors assessing “psychomotor disturbances”, “mixed instability” and “suicidality” delineate subtypes of patients characterized by the more severe forms of mood disorders, the higher risk for psychotic symptoms, and the lower quality of life after the remission of the full-blown-episode.

CONCLUSION: The mood spectrum model help researchers and clinicians in the systematic assessment of those areas of psychopathology that are still neglected by the Diagnostic and Statistical Manual of Mental Disorders 5 classification.

Biofeedback for treatment of awake and sleep bruxism in adults: systematic review protocol

BACKGROUND

Bruxism is a disorder of jaw-muscle activity characterised by repetitive clenching or grinding of the teeth which results in discomfort and damage to dentition. The two clinical manifestations of the condition (sleep and awake bruxism) are thought to have unrelated aetiologies but are palliated using similar techniques. The lack of a definitive treatment has prompted renewed interest in biofeedback, a behaviour change method that uses electronic detection to provide a stimulus whenever bruxism occurs. This systematic review aims to provide a comprehensive overview of the state of research into biofeedback for bruxism; to assess the efficacy and acceptability of biofeedback therapy in management of awake bruxism and, separately, sleep bruxism in adults; and to compare findings between the two variants.

METHODS

A systematic review of published literature examining biofeedback as an intervention directed at controlling primary bruxism in adults. We will search electronic databases and the grey literature using a predefined search strategy to identify randomised and non-randomised studies, technical reports and patents. Searches will not be restricted by language or date and will be expanded through contact with authors and experts, and by following up reference lists and citations. Two authors, working independently, will conduct screening of search results, study selection, data extraction and quality assessment and a third will resolve any disagreements. The primary outcomes of acceptability and effectiveness will be assessed using only randomised studies, segregated by bruxism subtype. A meta-analysis of these data will be conducted only if pre-defined conditions for quality and heterogeneity are met, otherwise the data will be summarized in narrative form. Data from non-randomised studies will be used to augment a narrative synthesis of the state of technical developments and any safety-related issues. PROSPERO registration number: CRD42013006880.

DISCUSSION

Biofeedback is not new, but its place in the clinical management of bruxism remains unclear. New research, and the availability of miniaturized consumer-grade devices, makes a systematic review timely to guide treatment decisions and inform future research.

Community based study of sleep bruxism during early childhood

OBJECTIVES

The aims for this study were to determine the prevalence of sleep-bruxism among young children, explore child behavior problems that may be associated with sleep-bruxism, and identify relations among sleep-bruxism, health problems, and neurocognitive performance.

METHODS

The current study was a retrospective analysis of parent report surveys, and behavioral and neurocognitive assessments. Parents of 1953 preschool and 2888 first grade children indicated their child's frequency of bruxism during sleep. A subsample of preschool children (n=249) had additional behavioral, as well as neurocognitive assessments. Among the subsample, parents also reported on their child's health, and completed the Child Behavioral Checklist; children were administered the Differential Ability Scales, and Pre-Reading Abilities subtests of the Developmental Neuropsychological Assessment.

RESULTS

36.8% of preschoolers and 49.6% of first graders were reported to brux ⩾1time per week. Among the preschool subsample, bruxing was independently associated with increased internalizing behaviors (β=.17). Bruxism was also associated with increased health problems (β=.19), and increased health problems were associated with decreased neurocognitive performance (β=.22).

CONCLUSIONS

The prevalence of sleep-bruxism was high. A dynamic and potentially clinically relevant relation exists among sleep-bruxism, internalizing behaviors, health, and neurocognition. Pediatric sleep-bruxism may serve as a sentinel marker for possible adverse health conditions, and signal a need for early intervention. These results support the need for an interdisciplinary approach to pediatric sleep medicine, dentistry, and psychology.

Nocturnal masseter muscle activity is related to symptoms and somatization in temporomandibular disorders

OBJECTIVE

Temporomandibular disorders (TMD) have often been related to sleep bruxism and elevated nocturnal masseter muscle activity (NMMA). However, previous studies have revealed controversial results, and the role of somatization, depression and anxiety has not been studied in this context. The aim of this study was to investigate the association between NMMA and pain intensity, TMD related symptoms, somatoform symptoms, depression, and anxiety in chronic TMD.

METHODS

Thirty-six subjects with chronic painful TMD, 34 subjects with pain free bruxism, and 36 healthy controls recorded their nocturnal masseter muscle activity during three consecutive nights with portable devices. In addition, participants completed pain diaries and questionnaires. Diagnoses were established using the research diagnostic criteria for TMD.

RESULTS

Subjects with chronic TMD reported a reduced general health state (p<.001), higher levels of somatoform symptoms (p<.001), depression (p<.05), and anxiety (p<.001) compared to control subjects with or without sleep bruxism. The amount of NMMA did not differ significantly between the groups. In subjects with TMD, pain intensity was not related to NMMA. However, higher NMMA was related to higher intensity of jaw related symptoms such as headache or tinnitus, and higher somatization in general.

CONCLUSION

Chronic TMD is associated with elevated levels of psychopathology. These findings suggest a common link between NMMA, somatization, and symptom intensity in chronic TMD.

Influence of psychological symptoms on home-recorded sleep-time masticatory muscle activity in healthy subjects

The present investigation attempts to describe the correlation between sleep-time masticatory muscle activity (MMA) and psychological symptoms by the use of a four-channel electromyography (EMG) home-recording device in a group of 15 healthy volunteers completing a battery of psychometric questionnaires for the assessment of anxiety, depression and anger. The integrated EMG signal was adopted to quantify the work (μV × s) produced by each of the four muscles (bilateral masseter and temporal) during the 5-h recording span and per each 1-h increment. The duration of MMA events and the muscle work during the first hour of sleep was related to trait anxiety scores for both masseter (P = 0·007) and temporalis muscles (P = 0·022). Trait anxiety was also significantly correlated to the total amount of MMA duration (in seconds) of the temporalis muscles (r = 0·558; P = 0·031). The present investigation provides support to the hypothesis that the duration of sleep-time masticatory muscle activity, especially during the early phases of a night's sleep, may be related to anxiety trait and not to anxiety state, depression or anger. These findings may support the view that features related to the individual management of anxiety, viz. trait, are likely to be more important than acute episodes of anxiety, viz. state, in the aetiology of sleep-time masticatory muscle activity. The role of other psychological symptoms is likely to be less important.

The Significance of Sub-Threshold Symptoms of Anxiety in the Aetiology of Bruxism

Bruxism is the oral parafunctional habit of clenching and grinding the teeth. It occurs mainly unconsciously, diurnally and/or nocturnally. It is considered an important contributory factor in the aetiology of myofascial pain and temporomandibular joint disorders and derangements. The aetiology of bruxism is considered to be multifactorial, involving both physiological and psychological factors. The aim of the study was to examine the relationship between the sub-threshold symptoms of anxiety and bruxism, using a spectrum model. Firstly, levels of anxiety were determined using the Spielberger State Trait Anxiety Inventory (STAI) and the Kessler-10 (K-10). Secondly, a tooth-wear score was determined by means of a clinical examination and dental casts. Thirdly, bruxism was rated on an ordinal scale according to specified criteria. A dualistic trend in the relationship between sub-threshold symptoms of anxiety and bruxism was observed in the results. In approximately half of the subjects with higher than average anxiety scores, bruxistic behaviour was found. This indicates the possibility of two groups with separate relationships. The dentist could play a role in recognizing that a patient may be experiencing anxiety, expressed through bruxism behaviour, and refer the patient for therapy or counselling. An understanding of the psychological factors involved in the aetiology of bruxism could foster a more holistic approach to the treatment of patients with signs of bruxism.

ADHD, bruxism and psychiatric disorders: does bruxism increase the chance of a comorbid psychiatric disorder in children with ADHD and their parents?

There is an association between bruxism and ADHD. No published data on psychiatric comorbidities in attention-deficit/hyperactivity disorder (ADHD) children with bruxism were found. There is no satisfying treatment method for children with bruxism. If we understand its comorbidities well, a better treatment method could come out. This study was conducted to compare the frequency of comorbid psychiatric disorders in the parents and their ADHD children with and without teeth grinding. It was hypothesized that there is no association between bruxism and prevalence of comorbid psychiatric disorders in children with ADHD and their parental psychopathology. Eighty-nine ADHD children without teeth grinding were compared with 32 ADHD children with teeth grinding. Their parental psychiatric disorders were also compared. Structured interviews were used to diagnose comorbid psychiatric disorders. The demographic characteristics of the children and their parents were not different between the groups. The only psychiatric disorder in children, which was associated with the groups was oppositional defiant disorder. The rate of conduct disorder, tic disorder, major depressive disorder, separation anxiety disorder, generalized anxiety disorder, enuresis, and obsessive compulsive disorder were not different between the two groups of children. The rate of major depression was more in the mothers of children with teeth grinding than those without such children. These finding were not reported before. ADHD children with teeth grinding have a high prevalence of oppositional defiant disorder. Lack of association between anxiety disorder and presence of teeth grinding might not support the idea that anxiety is associated with teeth grinding. The association of ODD and teeth girding might be a clue about etiology of bruxism. Perhaps, this clue can probably lead to the development of a more satisfying treatment. With consideration of this clue, further studies should survey if there is any association between ODD and sleep micro-arousals.