A comparison of different treatments for nocturnal bruxism

Effect of contingent vibratory stimulus via an oral appliance on sleep bruxism after the splint adaptation period

BACKGROUND

Contingent vibratory feedback stimuli applied by a specially designed oral appliance (OA) have been reported to be effective in reducing sleep bruxism (SB). However, the inhibitory effects of the OA, which occur immediately after OA delivery, may have confounded this finding.

OBJECTIVE

This study sought to shed light on the effects of vibratory stimuli on SB after the OA adaptation period, when its inhibitory effects are diminished.

METHODS

Fourteen 'definite' SB patients were enrolled. A force-based bruxism detection system was utilised to trigger a vibrator attached to the OA. Masseter electromyographic activity during sleep was recorded at home using portable polysomnography. After using the OA without vibratory stimulus for 16 nights (adaptation period), intermittent vibratory stimuli were applied every other half-hour for four nights (intervention period). Electromyographic activity over 10% of the maximum voluntary contraction was regarded as a SB episode. The number and the total duration of SB episodes per hour of sleep were calculated for the sessions with and without stimuli separately and averaged for four intervention nights. The effects of stimuli on these two variables were evaluated.

RESULTS

The number and the total duration of the sessions without stimuli were 5.2 episodes/h and 35.3 s/h, respectively. These values significantly decreased to 3.9 episodes/h and 15.1 s/h (p < .05) for the sessions with vibratory stimuli.

CONCLUSION

Contingent vibratory stimulus via an OA may be effective for the management of SB even after adaptation to OA.

Oral splints for temporomandibular disorder or bruxism: a systematic review

Objectives To evaluate the clinical-effectiveness of oral splints for patients with TMD or bruxism for the primary outcomes: pain (TMD) and tooth wear (bruxism).

Data sources Four databases including MEDLINE and EMBASE were searched from inception until 1 October 2018.

Data selection and extraction Randomised controlled trials comparing all types of splints versus no/minimal treatment for patients with TMD or bruxism were eligible. Standard Cochrane review methods were used. Standardised mean differences (SMD) were pooled for the primary outcome of pain, using random effects models in TMD patients.

Data synthesis Thirty-seven trials were included and the evidence identified was of very low certainty using GRADE assessments. When all subtypes of TMD were pooled into one global TMD group, there was no evidence that splints reduced pain: SMD (up to 3 months) -0.18 (95% CI -0.42 to 0.06); 13 trials, 1,076 participants. There was no evidence that any other outcomes improved when using splints. There was no evidence of adverse events associated with splints, but reporting was poor regarding this outcome. No trials measured tooth wear in patients with bruxism. There was a large variation in diagnostic criteria, splint types and outcome measures used and reported. Sensitivity analyses based on these factors did not indicate a reduction in pain.

Conclusions The very low-certainty evidence identified did not demonstrate that splints reduced pain in TMD as a group of conditions. There is insufficient evidence to determine whether splints reduce tooth wear in patients with bruxism.

Treatment of cerebral glioblastoma-caused bruxism with mirtazapine: a case report

BACKGROUND

Bruxism refers to grind or gnash the opposing rows of upper and lower molar teeth. It is important to treat bruxism as a factor that can influence sleep quality, quality of life, and mental status in patients with malignancy.

CASE PRESENTATION

A 41-year-old male developed bruxism secondary to cerebral glioblastoma. L-dopa, gabapentin, clonazepam, clonidine, baclofen, buspirone, or propranolol were not effective. Mirtazapine, prescribed for side effects of chemotherapy, was effective for bruxism, which was disappeared within 3 weeks.

CONCLUSIONS

Mirtazapine was effective for treating bruxism as well as chemotherapy complications.

Oral splints for patients with temporomandibular disorders or bruxism: a systematic review and economic evaluation

BACKGROUND

Splints are a non-invasive, reversible management option for temporomandibular disorders or bruxism. The clinical effectiveness and cost-effectiveness of splints remain uncertain.

OBJECTIVES

The objectives were to evaluate the clinical effectiveness and cost-effectiveness of splints for patients with temporomandibular disorders or bruxism. This evidence synthesis compared (1) all types of splint versus no/minimal treatment/control splints and (2) prefabricated versus custom-made splints, for the primary outcomes, which were pain (temporomandibular disorders) and tooth wear (bruxism).

REVIEW METHODS

Four databases, including MEDLINE and EMBASE, were searched from inception until 1 October 2018 for randomised clinical trials. The searches were conducted on 1 October 2018. Cochrane review methods (including risk of bias) were used for the systematic review. Standardised mean differences were pooled for the primary outcome of pain, using random-effects models in temporomandibular disorder patients. A Markov cohort, state-transition model, populated using current pain and Characteristic Pain Intensity data, was used to estimate the incremental cost-effectiveness ratio for splints compared with no splint, from an NHS perspective over a lifetime horizon. A value-of-information analysis identified future research priorities.

RESULTS

Fifty-two trials were included in the systematic review. The evidence identified was of very low quality with unclear reporting by temporomandibular disorder subtype. When all subtypes were pooled into one global temporomandibular disorder group, there was no evidence that splints reduced pain [standardised mean difference (at up to 3 months) -0.18, 95% confidence interval -0.42 to 0.06; substantial heterogeneity] when compared with no splints or a minimal intervention. There was no evidence that other outcomes, including temporomandibular joint noises, decreased mouth-opening, and quality of life, improved when using splints. Adverse events were generally not reported, but seemed infrequent when reported. The most plausible base-case incremental cost-effectiveness ratio was uncertain and driven by the lack of clinical effectiveness evidence. The cost-effectiveness acceptability curve showed splints becoming more cost-effective at a willingness-to-pay threshold of ≈£6000, but the probability never exceeded 60% at higher levels of willingness to pay. Results were sensitive to longer-term extrapolation assumptions. A value-of-information analysis indicated that further research is required. There were no studies measuring tooth wear in patients with bruxism. One small study looked at pain and found a reduction in the splint group [mean difference (0-10 scale) -2.01, 95% CI -1.40 to -2.62; very low-quality evidence]. As there was no evidence of a difference between splints and no splints, the second objective became irrelevant.

LIMITATIONS

There was a large variation in the diagnostic criteria, splint types and outcome measures used and reported. Sensitivity analyses based on these limitations did not indicate a reduction in pain.

CONCLUSIONS

The very low-quality evidence identified did not demonstrate that splints reduced pain in temporomandibular disorders as a group of conditions. There is insufficient evidence to determine whether or not splints reduce tooth wear in patients with bruxism. There remains substantial uncertainty surrounding the most plausible incremental cost-effectiveness ratio.

FUTURE WORK

There is a need for well-conducted trials to determine the clinical effectiveness and cost-effectiveness of splints in patients with carefully diagnosed and subtyped temporomandibular disorders, and patients with bruxism, using agreed measures of pain and tooth wear.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017068512.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 7. See the NIHR Journals Library website for further project information.

Periodontal Regenerative Therapy with Enamel Matrix Derivative in Patient with Chronic Periodontitis: A 3.5-year Follow-up Report

Here, we report periodontal treatment including regenerative therapy in a patient with generalized chronic periodontitis. The patient was a 53-year-old woman who presented with the chief complaint of gingival swelling and tooth mobility in the right maxillary molar region. An initial examination revealed 36% of sites with a probing depth of ≥4 mm and 15.5% with bleeding on probing. Radiographic examination revealed vertical bone resorption in #15, 24, 27, 34, 37, 45, and 47. Horizontal resorption was noted in other regions. The clinical diagnosis was moderate chronic periodontitis. Initial periodontal therapy consisted of plaque control, scaling, and root planing together with treatment for caries. Occlusal adjustment of premature contact sites was performed after suppression of inflammation. Periodontal regenerative therapy using enamel matrix derivative was performed on #15, 24, 34, 45, and 47. Other sites with residual periodontal pockets were treated by open flap debridement. Tooth #27 was extracted due to a bone defect exceeding the root apex; #37 was extracted due to frequent acute symptoms following periodontal surgery. Following re-evaluation, the patient was placed on supportive periodontal therapy. Periodontal regenerative therapy improved vertical bone resorption. This improvement has been adequately maintained over a 3 years 6 months period. Additional care is necessary, however, to further improve the patient's oral health-related quality of life during supportive periodontal therapy.

Home Polysomnography Reveals a First-Night Effect in Patients With Low Sleep Bruxism Activity

STUDY OBJECTIVES

To examine the presence of a first-night effect (FNE) and the level of internight variability in sleep bruxism (SB) activity when a self-applicable electrode set is used in home polysomnography (PSG) in a sample of subjects with possible SB.

METHODS

Fourteen females and two males aged 38.3 ± 9.1 years (mean ± standard deviation) with self-reported SB underwent home-PSG on three consecutive nights. The subjects applied PSG sensors themselves, including self-applicable electrode sets used to record sleep and masseter muscle activity. Repeated-measures analysis of variance was used to compare SB and sleep variables between the nights.

RESULTS

Surprisingly, there were statistically significant elevations in the rhythmic masticatory muscle activity (RMMA) episode index (P = .009), burst index (P = .016), and bruxism time index (P = .049) throughout the course of 3 nights. More bruxers were diagnosed on the second (6 bruxers, ≥ 2 episodes/h) and third night (7 bruxers) compared to the first night (2 bruxers). Most subjects (14/16) had their highest RMMA index on the second or third night. The mean coefficient of variation for RMMA episode index was 50.7%. No statistically significant differences were detected in other sleep variables.

CONCLUSIONS

The results indicate that a FNE may be present in SB activity, possibly lasting several nights in some subjects. Furthermore, FNE appears to be combined with high internight variability of SB activity without indications of internight changes in sleep macrostructure. To confirm the level of ongoing SB activity, several nights of PSG may be required, especially in subjects with low first-night SB activity.

COMMENTARY

A commentary on this article appears in this issue on page 1281.

The effects of stabilization splint treatment on the volume of masseter muscle in sleep bruxism patients

OBJECTIVE

The aim of this study was to evaluate, quantitatively, the volumetric effects of stabilization splint therapy on the masseter muscle of sleep bruxism (SB) patients.

METHODS

The magnetic resonance (MR) images of 16 SB patients diagnosed by polysomnography (PSG) who used stabilization splints for four months were obtained before and after the therapy. The masseter muscle volume was calculated using Cavalieri's principle on the MR images.

RESULTS

After the splint therapy, the mean volume of the masseter muscle did not reduce significantly. The fat and/or water content of the muscles did not change either.

DISCUSSION

The stabilization splint therapy had no effect on the volume, fat and/or water content of the masseter muscle; however the discomfort was reduced in the patients. Although the effect of splint therapy is not fully understood, the non-invasive and reversible stabilization splint can be used in SB patients because of its relaxation effect on muscles.

Electromyographic biofeedback training for reducing muscle pain and tension on masseter and temporal muscles: A pilot study

Background

Due to the absence of agreement about an effective unified treatment for temporomandibular disorders, non-invasive therapies such as EMG-biofeedback generate a greater interest. Furthermore, most studies to the present show methodological deficiencies that must be solved in the future, which makes important to emphasize this line of studies.

Material and Methods

Fourteen patients were selected for this case series study, and replied to a questionnaire concerning awareness of bruxism, painful muscles, and muscle tension. They also practiced an intraoral exploration (occlusal analysis and mandibular dynamics), and an extraoral exploration of the head and neck muscles and the temporomandibular joint. Before each session, patients responded to a questionnaire about the subjective perceived improvement. In each session, a period of three minutes of pre-biofeedback EMG activity of right masseter and temporal muscles was registered, then patients performed 30 iterations of visual EMG-biofeedback training and finally, a period of three minutes of post-EMG activity was also registered for those muscles. Patients performed four sessions.

Results

A decrease in painful symptoms was found for all patients since the first session. EMG activity decreases (p<0,05) in both muscles during the biofeedback training stage, in the four sessions. It is also observed a decrease (p<0,05) in EMG activity in the masseter muscle at the post-biofeedback stage, in the second and third sessions. There is likewise a decrease in EMG post-biofeedback activity of the temporal muscle (p<0,05) in sessions two, three, and four.

Conclusions

EMG-biofeedback training produces a decrease in EMG activity in both masseter and temporal muscles during the session. This decrease persists during the post-biofeedback period since the second session. Also there is a decrease in painful symptoms for all patients.

Key words:Muscle tension, muscle pain, EMG-biofeedback, masseter muscle, temporal muscle.

[Craniomandibular disorder/dysfunction. Characteristics and disorders of the masticatory organ]

The practising physician often meets patients with pain located in different parts of the face and facial skull, mouth opening restriction or other motion disorder of the mandible. It is not always easy to identify and explain the cause. It is not widely known among doctors that most of these problems are due to masticatory dysfunction. There is a special group of patients showing functional disorders and there are some others who present a variety of different symptoms and visit several doctors. The masticatory organ, a functional unit of the human organism has a definite and separate task and function. In the early years of life it is capable of adaptation, while later on it tends to compensation. The authors outline the functional anatomy of the masticatory organ and the characteristics of multicausal pathology, the dynamics of the process of the disease and their interdisciplinary aspects. They discuss the basic elements of craniomandibular dysfunction. Based on the diagnostic algorithm, they summarize treatment options for masticatory function disorders. They emphasize the importance that physicians should offer treatment, especially an irreversible treatment, without a diagnosis. It occurs very often that the causes are identified after the patients become symptom-free due to treatment. The aim of this report is to help the general practitioners, dentists, neurologists, ear-nose-throat specialists, rheumatologists or any other specialists in the everyday practice who have patients with different symptoms such as pain in the skull, acoustic phenomenon of the joint or craniomandibular dysfunction.

The efficacy of gabapentin versus stabilization splint in management of sleep bruxism

PURPOSE

This study aimed to determine if the use of gabapentin is more efficacious than a stabilization splint with regard to the intensity of masseter muscle contractions and/or sleep quality for patients experiencing sleep bruxism (SB).

MATERIALS AND METHODS

Twenty patients with SB participated in this clinical study. They were randomly divided into two treatment groups: stabilization splint group (n = 10) and gabapentin group (n = 10). The first polysomnographic examination was performed before the beginning of the experiment for all the participants. At the end of a 2-month period of stabilization splint therapy or gabapentin usage, a second polysomnographic recording was made.

RESULTS

Statistically significant reductions in the number of SB episodes per hour and per night, bruxism time index, total duration of SB episodes per night and number of SB episodes in stages NR I and NR II (p < 0.05) were observed in both groups after treatment. Both treatments significantly reduced the mean intensity of masseter muscle contractions during SB episodes. Moreover, the participants treated with gabapentin showed a significant improvement in total sleep time, slow wave sleep (stage III), and sleep efficiency (p < 0.05).

CONCLUSIONS

Gabapentin could be an effective treatment modality in SBs, especially in those with poor sleep quality.

Craniofacial Pain and Jaw-muscle Activity during Sleep

This study compared the jaw-muscle electromyographic (EMG) activity during sleep in patients with craniofacial pain (n = 63) or no painful conditions (n = 52) and between patients with tension-type headache (TTH: n = 30) and healthy control individuals (n = 30). All participants used a portable single-channel EMG device (Medotech A/S) for four nights. There was no significant difference in EMG activity between craniofacial pain (24.5 ± 17.9 events/hr) and no painful conditions (19.7 ± 14.5), or between TTH (20.8 ± 15.0) and healthy control individuals (15.2 ± 11.6, p >.050). There were positive correlations between EMG activity and number of painful muscles (r = 0.188; p = 0.044), characteristic pain intensity (r = 0.187; p = 0.046), McGill Pain Questionnaire (r = 0.251; p = 0.008), and depression scores (r = 0.291; p = 0.002). Patients with painful conditions had significantly higher night-to-night variability compared with pain-free individuals (p < 0.050). This short-term observational study suggests that there are no major differences between patients with different craniofacial pain conditions and pain-free individuals in terms of jaw-muscle EMG activity recorded with a single-channel EMG device during sleep. However, some associations may exist between the level of EMG activity and various parameters of craniofacial pain. Longitudinal studies are warranted to further explore the relationship between sleep bruxism and craniofacial pain.

Sleep-related movement disorders

Several movement disorders may occur during nocturnal rest disrupting sleep. A part of these complaints is characterized by relatively simple, non-purposeful and usually stereotyped movements. The last version of the International Classification of Sleep Disorders includes these clinical conditions (i.e. restless legs syndrome, periodic limb movement disorder, sleep-related leg cramps, sleep-related bruxism and sleep-related rhythmic movement disorder) under the category entitled sleep-related movement disorders. Moreover, apparently physiological movements (e.g. alternating leg muscle activation and excessive hypnic fragmentary myoclonus) can show a high frequency and severity impairing sleep quality. Clinical and, in specific cases, neurophysiological assessments are required to detect the presence of nocturnal movement complaints. Patients reporting poor sleep due to these abnormal movements should undergo non-pharmacological or pharmacological treatments.

Controlled clinical, polysomnographic and psychometric studies on differences between sleep bruxers and controls and acute effects of clonazepam as compared with placebo

The pathogenesis, pathophysiology, and pharmacotherapy of sleep bruxism (SB) are still not fully understood. We investigated symptomatology, objective and subjective sleep and awakening quality of middle-aged bruxers compared with controls and acute effects of clonazepam 1 mg compared with placebo by polysomnography and psychometry. Twenty-one drug-free bruxers spent 3 nights in the sleep lab, 21 age- and sex-matched controls 2 nights. Clinically, bruxers exhibited deteriorated PSQI, SAS, SDS and IRLSSG measures, polysomnographically impaired sleep maintenance, increased movement time, stage shift index, periodic leg movements (PLM) and arousals and psychometrically deteriorated subjective sleep and awakening quality, evening/morning well-being, drive, mood, drowsiness, attention variability, memory, and fine motor activity. As compared with placebo, clonazepam significantly decreased the SB index in all patients (mean: -42 +/- 15%). Sleep efficiency, maintenance, latency, awakenings and nocturnal wake time, the stage shift index, S1, PLM, the arousal index, subjective sleep and awakening quality, and fine motor activity improved.

Identification of the occurrence and pattern of masseter muscle activities during sleep using EMG and accelerometer systems

BACKGROUND

Sleep bruxism has been described as a combination of different orofacial motor activities that include grinding, clenching and tapping, although accurate distribution of the activities still remains to be clarified.

METHODS

We developed a new system for analyzing sleep bruxism to examine the muscle activities and mandibular movement patterns during sleep bruxism. The system consisted of a 2-axis accelerometer, electroencephalography and electromyography. Nineteen healthy volunteers were recruited and screened to evaluate sleep bruxism in the sleep laboratory.

RESULTS

The new system could easily distinguish the different patterns of bruxism movement of the mandible and the body movement. Results showed that grinding (59.5%) was most common, followed by clenching (35.6%) based on relative activity to maximum voluntary contraction (%MVC), whereas tapping was only (4.9%).

CONCLUSION

It was concluded that the tapping, clenching, and grinding movement of the mandible could be effectively differentiated by the new system and sleep bruxism was predominantly perceived as clenching and grinding, which varied between individuals.

Muscle disorders and dentition-related aspects in temporomandibular disorders: controversies in the most commonly used treatment modalities

This review explores the aetiology of temporomandibular disorders and discusses the controversies in variable treatment modalities.Pathologies of the temporomandibular joint (TMJ) and its' associated muscles of mastication are jointly termed temporomandibular disorders (TMDs).TMDs present with a variety of symptoms which include pain in the joint and its surrounding area, jaw clicking, limited jaw opening and headaches. It is mainly reported by middle aged females who tend to recognize the symptoms more readily than males and therefore more commonly seek professional help.Several aetiological factors have been acknowledged including local trauma, bruxism, malocclusion, stress and psychiatric illnesses. The Research Diagnostic Criteria of the Temporomandibular Disorders (RDC/TMD) is advanced to other criteria as it takes into consideration the socio-psychological status of the patient.Several treatment modalities have been recommended including homecare practices, splint therapy, occlusal adjustment, analgesics and the use of psychotropic medication; as well as surgery, supplementary therapy and cognitive behavioural therapy. Although splint therapy and occlusal adjustment have been extensively used, there is no evidence to suggest that they can be curative; a number of evidence-based trials have concluded that these appliances should not be suggested as part of the routine care.Surgery, except in very rare cases, is discouraged since it is the most invasive alternative; recent studies have shown healthier outcome with cognitive behavioural therapy.

Occlusal splints for treating sleep bruxism (tooth grinding)

BACKGROUND

Sleep bruxism is an oral activity characterised by teeth grinding or clenching during sleep. Several treatments for sleep bruxism have been proposed such as pharmacological, psychological, and dental.

OBJECTIVES

To evaluate the effectiveness of occlusal splints for the treatment of sleep bruxism with alternative interventions, placebo or no treatment.

SEARCH STRATEGY

We searched the Cochrane Oral Health Group's Trials Register (to May 2007); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1); MEDLINE (1966 to May 2007); EMBASE (1980 to May 2007); LILACS (1982 to May 2007); Biblioteca Brasileira de Odontologia (1982 to May 2007); Dissertation, Theses and Abstracts (1981 to May 2007); and handsearched abstracts of particular importance to this review. Additional reports were identified from the reference lists of retrieved reports and from article reviews about treating sleep bruxism. There were no language restrictions.

SELECTION CRITERIA

We selected randomised or quasi-randomised controlled trials (RCTs), in which splint therapy was compared concurrently to no treatment, other occlusal appliances, or any other intervention in participants with sleep bruxism.

DATA COLLECTION AND ANALYSIS

Data extraction was carried out independently and in duplicate. Validity assessment of the included trials was carried out at the same time as data extraction. Discrepancies were discussed and a third review author consulted. The author of the primary study was contacted when necessary.

MAIN RESULTS

Thirty-two potentially relevant RCTs were identified. Twenty-four trials were excluded. Five RCTs were included. Occlusal splint was compared to: palatal splint, mandibular advancement device, transcutaneous electric nerve stimulation, and no treatment. There was just one common outcome (arousal index) which was combined in a meta-analysis. No statistically significant differences between the occlusal splint and control groups were found in the meta-analyses.

AUTHORS' CONCLUSIONS

There is not sufficient evidence to state that the occlusal splint is effective for treating sleep bruxism. Indication of its use is questionable with regard to sleep outcomes, but it may be that there is some benefit with regard to tooth wear. This systematic review suggests the need for further investigation in more controlled RCTs that pay attention to method of allocation, outcome assessment, large sample size, and sufficient duration of follow up. The study design must be parallel, in order to eliminate the bias provided by studies of cross-over type. A standardisation of the outcomes of the treatment of sleep bruxism should be established in the RCTs.

The effect of oral splint devices on sleep bruxism: a 6-week observation with an ambulatory electromyographic recording device

This study investigated the effect of stabilization splint (SS) and palatal splint (PS), which had the same design as SS except for the elimination of the occlusal coverage, on sleep bruxism (SB) using a portable electromyographic (EMG) recording system. Sixteen bruxers participated in this study. The EMG activities of the right masseter muscle during sleep were recorded for three nights each in the following five recording periods: before, immediately after, and 2, 4 and 6 weeks after the insertion of the splint. The crossover design, in which each splint was applied to each subject for 6 weeks with an interval of 2 months for a washout period, was employed in this randomized-controlled study. The number of SB events, duration and total activities of SB were analysed. The number of SB events before the insertion of splints (baseline) was 2.98 +/- 1.61 times h(-1). Both splints significantly reduced SB immediately after the insertion of devices (P < 0.05, one-way repeated-measures anova followed by Dunnett); however, no reduction was observed in 2, 4 or 6 weeks (P > 0.05). There was no statistical difference in the effect on SB between the SS and PS (P > 0.05, two-way repeated-measures anova). Both splints reduced the masseter EMG activities associated with SB; however, the effect was transient.

Bilateral temporalis muscle hypertrophy: a case report

Although masseteric hypertrophy is common and can be accompanied by temporalis hypertrophy, temporalis hypertrophy by itself is an exceptional finding. A patient, a chronic bruxer who was receiving psychiatric care and psychotherapeutic medications, complained of moderate discomfort and swelling in both temporal areas. It is believed that the patient's long-term stress-related sleeping problem was causing her bruxism. Of great interest was the fact that chronic bruxing had resulted in the rare occurrence of temporalis muscle hypertrophy without a coexisting masseteric hypertrophy.

On the pharmacotherapy of sleep bruxism: placebo-controlled polysomnographic and psychometric studies with clonazepam

OBJECTIVES

Sleep bruxism (SB) is a parasomnia defined as a stereotyped movement disorder characterized by grinding or clenching of the teeth during sleep. Pathophysiologically, SB is the result of biological and psychosocial influences. Treatment comprises behavioral, orthodontic and pharmacological interventions. While benzodiazepines and muscle relaxants have been reported by clinicians to reduce bruxism-related motor activity, placebo-controlled studies are lacking. Thus, the aim of the present study was to investigate the acute effects of clonazepam (Rivotril) as compared with placebo, utilizing polysomnography and psychometry.

METHOD

Ten drug-free outpatients (6 females, 4 males), aged 46.5 +/- 13.1 years, suffering from SB (ICD-10: F45.8; ICSD: 306.8) and having been treated by bite splints were included in the trial. Comorbidity was high: 7 patients presented nonorganic insomnia related to adjustment or anxiety disorders (5 patients) or depression (2 patients); all patients had a concomitant movement disorder (6 restless legs syndrome, 4 periodic leg movement disorder). After one adaptation night, patients received placebo and 1 mg clonazepam 1/2 hour before lights out in a single-blind, nonrandomized study design. Objective sleep quality was determined by polysomnography, subjective sleep and awakening quality by rating scales, objective awakening quality by psychometric tests. Clinical evaluation was based on the Pittsburgh Sleep Quality Index (PSQI), the Zung Depression (SDS) and Anxiety (SAS) Scales, the Quality of Life Index, the Epworth Sleepiness Scale and the International Restless Legs Syndrome Study Group (IRLSSG) Scale.

RESULTS

On admission, SB patients exhibited deteriorated PSQI, SAS, SDS and IRLSSG measures. As compared with placebo, 1 mg clonazepam significantly improved the mean bruxism index from 9.3 to 6.3/h of sleep. Furthermore, it significantly improved the total sleep period, total sleep time, sleep efficiency, sleep latency and time awake during the total sleep period, and increased stage 2 sleep and movement time. Periodic leg movements decreased significantly, while the apnea index and apnea-hypopnea index increased marginally, but remained within normal limits. Subjective sleep quality improved as well, while in mood, performance and psychophysiology no changes were observed.

CONCLUSION

Acute clonazepam therapy significantly improved not only the bruxism index but also objective and subjective sleep quality, with unchanged mood, performance and psychophysiological measures upon awakening, suggesting good tolerability of the drug.

Salivary flow rates during relaxing, clenching, and chewing-like movement with maxillary occlusal splints

The purpose of this study was to test the hypothesis that the application of occlusal splints increases the diurnal salivary flow rate both in bruxism patients and in normal subjects. Salivary flow rates in 16 adult volunteers (8 bruxism patients and 8 sex- and age-matched control subjects) were measured with the spitting method. There was no significant difference in the salivary flow rate with or without splints between the control and bruxism groups. In all subjects, the salivary flow rates with splints were significantly higher than those without splints during relaxing, clenching, and chewing-like movement. The salivary flow rate during the chewing-like movement was significantly higher than that during relaxing and clenching, irrespective of splint application. The results suggest that maxillary occlusal splints might stimulate salivary secretion, particularly during chewing-like movement, in both bruxism patients and normal subjects.

Non-rapid eye movement parasomnias

Non-rapid eye movement parasomnias are unique physical or experiential phenomena that disrupt sleep. Non-rapid eye movement parasomnias are common in children, but they typically outgrow them. Sleep-stage shifts caused by sleep-disordered breathing and associated arousals may be precipitating events for episodes of parasomnia. Seizure disorders should always be considered in the differential diagnosis for the evaluation of parasomnias. Violent or injurious sleepwalking should be rapidly evaluated and treated.

Quantitative polygraphic controlled study on efficacy and safety of oral splint devices in tooth-grinding subjects

The efficacy of occlusal splints in diminishing muscle activity and tooth-grinding damage remains controversial. The objective of this study was to compare the efficacy and safety of an occlusal splint (OS) vs. a palatal control device (PCD). Nine subjects with sleep bruxism (SB) participated in this randomized study. Sleep laboratory recordings were made on the second night to establish baseline data. Patients then wore each of the splints in the sleep laboratory for recording nights three and four, two weeks apart, according to a crossover design. A statistically significant reduction in the number of SB episodes per hour (decrease of 41%, p = 0.05) and SB bursts per hour (decrease of 40%, p < 0.05) was observed with the two devices. Both oral devices also showed 50% fewer episodes with grinding noise (p = 0.06). No difference was observed between the devices. Moreover, no changes in respiratory variables were observed. Both devices reduced muscle activity associated with SB.

Contingent electrical lip stimulation for sleep bruxism: a pilot study

STATEMENT OF PROBLEM

No effective method has been found to fully control sleep bruxism, although contingent feedback methods show some promise.

PURPOSE

This demonstration-of-concept study evaluated the effect of contingent electrical lip stimulation on sleep bruxism.

MATERIAL AND METHODS

Recordings of masseter muscle activity were performed over 5 nights in 7 subjects with acknowledged bruxism and dental attrition (5 men, 2 women). A small electrical switch, activated with light force clenching, was mounted between 2 occlusal orthotics. This switch triggered a stimulator, which delivered slightly noxious electrical pulses to the subject's lip. After a baseline first night recording session, stimulation was delivered in 1-hour blocks for half of each sleep period during nights 2 through 5. Paired t tests (alpha = 0.05) were conducted on 4 recorded bruxism parameters.

RESULTS

With stimulation, the number (+/-SD) of events/hour reduced from a baseline level of 3.9 +/- 2.0 to 2.4 +/- 0.8 and the mean amplitude (% maximum voluntary contraction) reduced from 28.7 +/- 20.0 to 17.6 +/- 4.1. There was a mean decrease in the duration (s/event) from 10.6 +/- 1.4 to 9.1 +/- 2.5 and the total event time (s/hour) was reduced from 41.7 +/- 22.4 to 23.2 +/- 11.0. Among these measures, bruxism events with and without stimulation were compared, and only the duration of individual bruxism events (s/event) showed a significant change (P=.038). Finally, no subject reported being awakened from sleep by the stimulation.

CONCLUSION

The reductions in bruxism events were noteworthy, especially considering that stimulation was delivered for only half of the sleeping period.

Hypnorelaxation as treatment for myofascial pain disorder: a comparative study

BACKGROUND

Hypnorelaxation has a potentially beneficial effect in the treatment of masticatory myofascial pain disorders (MPD). However, there are no data regarding the efficacy of hypnorelaxation in the treatment of MPD compared with other accepted modes of treatment (such as occlusal appliance) or with the mere effect of time.

OBJECTIVE AND SUBJECTS

The purpose of the present study was to evaluate the effectiveness of hypnorelaxation in the treatment of MPD compared with the use of occlusal appliance and/or to minimal treatment. The study population consisted of 40 female patients with myofascial pain who were allocated to 1 of 3 possible treatment groups: (1) hypnorelaxation (n = 15), (2) occlusal appliance (n = 15), and (3) minimal treatment group (n = 10).

RESULTS

Both active treatment modes (hypnorelaxation and occlusal appliance) were more effective than minimal treatment regarding alleviating muscular sensitivity to palpation. However, only hypnorelaxation (but not occlusal appliance) was significantly more effective than minimal treatment with regard to the patient's subjective report of pain on the Visual Analog Scale.

CONCLUSION

Hypnorelaxation is an effective mode of treatment in MPD, especially with regard to some of the subjective pain parameters.

Migraine and tension-type headache reduction through pericranial muscular suppression: a preliminary report

Migraine and tension-type headaches have always plagued mankind. In spite of all the research dollars spent trying to determine the etiologies of these headaches, the neurology community still has not established a known cause of migraine and tension type headaches. This paper describes a study that was conducted for the U.S. Food and Drug Administration in which the efficacy of the Nociceptive Trigeminal Inhibition Tension Suppression System was evaluated and proved safe and efficacious in the reduction of medically diagnosed migraine and tension-type headache.

Masticatory muscle activity assessment and reliability of a portable electromyographic instrument

STATEMENT OF PROBLEM

Masticatory muscle hyperactivity is thought to produce muscle pain and tension headaches and can cause excessive wear or breakage of restorative dental materials used in the treatment of prosthodontic patients. The quantification and identification of this type of activity is an important consideration in the preoperative diagnosis and treatment planning phase of prosthodontic care.

PURPOSE

This study investigated the quantification process in complete denture/overdenture patients with natural mandibular tooth abutments and explored the reliability of instrumentation used to assess this parafunctional activity.

MATERIAL AND METHODS

The nocturnal EMG activity in asymptomatic complete denture/overdenture subjects was assessed with and without prostheses worn during sleep. Because of the large variance within and between subjects, the investigators evaluated the reliability of the 3 instruments used to test nocturnal EMG activity in the sample.

RESULTS

Electromyographic activity data of denture/overdenture subjects revealed no differences between prostheses worn versus not worn during sleep but demonstrated a very large variance factor. Further investigation of the instrumentation demonstrated a consistent in vitro as well as in vivo reliability in controlled laboratory studies.

CONCLUSION

The portable EMG instrumentation used in this study revealed a large, uncontrollable variance factor within and between subjects that greatly complicated the diagnosis of parafunctional activity in prosthodontic patients.

Profile of TMD and Bruxer compared to TMD and nonbruxer patients regarding chief complaint, previous consultations, modes of therapy, and chronicity

This comparative study by groups assesses the profiles of TMD (temporomandibular dysfunction) and bruxism patients and TMD-nonbruxing patients regarding chief complaint, previous medical and dental consultations, duration of the chief complaint, previous medication, and use of splints. The sample consisted of a group of 340 TMD patients, 275 of whom were bruxers and 65 who were nonbruxers. Both patients and controls were consecutive referrals over a period of five years. The group of TMD and Bruxer was classified according to the degree of severity. One hundred eight (108), 84, and 83 patients demonstrated mild, moderate, and severe bruxism respectively. Information gathered included a set of questionnaires, history of signs and symptoms, and a clinical examination. The most common chief complaints in TMD bruxers and nonbruxers were facial, temporomandibular joint, headache and/or cervical pain, and joint noises. It was observed that the need for medical and dental consultations increased with the severity of bruxism. It was also apparent in this study that the need for medication (analgesics, muscle relaxants, and antidepressants), increased with the severity of bruxism. Moderate and severe subgroups of bruxers used significantly more splints compared to mild bruxers and to TMD-nonbruxer patients. Both groups of TMD + bruxism and TMD - nonbruxism sought medical and dental consultations with dentists (clinicians and specialists) neurologists, and otolaryngologists more frequently compared to other medical professionals. Since the need for health services increased with the severity of bruxism, this study urges the need to include a protocol or questionnaire to assess the severity of bruxing behavior in TMD patients in order to use a customized method of treatment/management. This study also reinforces the point of view that different subgroups of TMD and bruxism do exist and suggests a differentiated therapeutic approach. They show previously confirmed findings that pain is the major complaint of TMD and bruxer patients.

Sleep bruxism; an overview of an oromandibular sleep movement disorder. REVIEW ARTICLE

Sleep bruxism (SB) is a stereotyped movement disorder characterized by grinding or clenching of the teeth during sleep. The majority of the population will at some time during their lifetime grind or clench their teeth. It becomes a pathological condition when the subject presents severe tooth damage or complains of non-restorative sleep. The prevalence of SB is difficult to estimate, since quite often the subjects are unaware of having the disorder. There is no gender difference. SB is more frequent in the younger generation, with a decline over age. The symptom recognized in children can persist in adulthood. The aetio-pathophysiology is still unclear. SB has been associated with tooth interference, psychosocial and environmental factors, brain transmitters and basal ganglia dysfunction. Attempts have been made to specify the personality traits of bruxers, reported to be greater anxiety or vulnerability to stress; however, this is still controversial. SB subjects were observed to present vigilance-sleepiness and somatic problems. However, they are generally good sleepers. Some authors reported SB during all sleep stages, others observed the majority of bruxe episodes during light sleep and REM and often associated with arousal transients. No abnormalities of the autonomic nervous system could be shown in awake SB subjects. While some studies have shown an association between SB and PLM or breathing disorders, others did not confirm this. There is no specific treatment for SB: each subject has to be individually evaluated and treated. Three management alternatives are used: dental, pharmacological and psychobehavioural.

Sleep disorders and the dental patient: an overview

This article is intended to briefly describe common sleep disorders of interest to the dental profession and to render general management guidelines. Topics include sleep-related bruxism, xerostomia, hypersalivation, gastroesophageal reflux, apnea, and the effect of orofacial pain on sleep quality. The term sleep-related is used instead of the term nocturnal because some of the activities described can occur with daytime sleep.

Bruxism and cranial-cervical dystonia: is there a relationship?

To characterize the relationship between bruxism and dystonia, 79 patients (28 men and 51 women) with cranial-cervical dystonia were studied. Sixty-two patients (78.5%), 22 men and 40 women, had bruxism. The mean age at onset of dystonia in patients with bruxism was 52.4 +/- 12.6 years (range 14-80), similar to patients with cranial-cervical dystonia without bruxism. Involuntary oromandibular movements (46 patients) and blepharospasm (34 patients) were the most common initial symptoms among patients with dystonia. About one-fourth of bruxism patients had associated dental problems including TMD (21%) and tooth wear (5%). A majority (58%) of the bruxism patients had diurnal bruxism and 12% had nocturnal bruxism. The bruxism patients were compared to 100 patients with Parkinson's disease (PD), cervical dystonia, cranial dystonia, and normal controls, respectively. The prevalence of bruxism was much higher in the cranial-cervical dystonia patients when compared to normal controls (P < 0.001); however, this difference was not significant between other diseased groups and controls. Medications and botulinum toxin injections, used in the treatment of focal dystonia also provided effective relief of bruxism.

Oral splints: the crutches for temporomandibular disorders and bruxism?

Despite the extensive use of oral splints in the treatment of temporomandibular disorders (TMD) and bruxism, their mechanisms of action remain controversial Various hypotheses have been proposed to explain their apparent efficacy (i.e., true therapeutic value), including the repositioning of condyle and/or the articular disc, reduction in the electromyographic activity of the masticatory muscles, modification of the patient's "harmful" oral behavior, and changes in the patient's occlusion. Following a comprehensive review of the literature, it is concluded that any of these theories is either poor or inconsistent, while the issue of true efficacy for oral splints remains unsettled. However, the results of a controlled clinical trial lend support to the effectiveness (i.e., the patient's appreciation of the positive changes which are perceived to have occurred during the trial) of the stabilizing splint in the control of myofascial pain. In light of the data supporting their effectiveness but not their efficacy, oral splints should be used as an adjunct for pain management rather than a definitive treatment. For sleep bruxism, it is prudent to limit their use as a habit management aid and to prevent/limit dental damage potentially induced by the disorder. Future research should study the natural history and etiologies of TMD and bruxism, so that specific treatments for these disorders can be developed.

Automatic on-line one-channel recognition of masseter activity

The etiology of myoarthropathies of the masticatory system (MAP) is not fully understood. For the hypothetical association between the myogenous pain of MAP patients and masticatory muscle overuse to be proved, functional and parafunctional behavior of the masticatory muscles should be analyzed in normal and diseased subjects. The aim of this study was to test on-line the validity and reliability of an algorithm, applied to the electromyographic signal, to recognize various oral activities. The surface electromyogram of the masseter muscle was recorded in 12 subjects (seven females and five males, from 18 to 32 years old) who performed a series of functional and parafunctional activities (chewing soft food, chewing hard food, swallowing, laughing, speaking, and tooth grinding and clenching), as well as no activity. During the computer training phase, intra-individual classification functions of a multivariate discriminant analysis were calculated while each subject performed the described activities. During the test phase, each subject repeated the same activities, and the computer continuously classified them on-line. The percentage of correctly recognized activities was calculated for each activity and for each subject. No activity, chewing hard food, swallowing, laughing, grinding, and clenching were recognized correctly > 99% of the time. Chewing soft food was recognized correctly 97% and speaking 86% of the time. The sensitivity values for the recognition rates of the complete oral activities were, with one exception, > 0.82; the specificity values were > 0.95, and the kappa-values > 0.80. These results show that the algorithm had high sensitivity, specificity, and reliability in the classification of different oral activities under laboratory conditions.

Effect of muscle relaxation splint therapy on the electromyographic activities of masseter and anterior temporalis muscles

The purpose of this study was to compare the effectiveness of splint therapy on the electromyographic activity of masticatory muscles (anterior temporalis and masseter) before and after the application of a muscle relaxation splint. Electromyography recordings from the masseter and anterior temporalis muscles were analyzed quantitatively during maximal biting in the intercuspal position both before and after treatment without a splint. Fourteen patients whose chief complaint was masticatory muscle pain were selected for the study. After the initial evaluations muscle relaxation splints were applied, and the patients were instructed to use the splints for 6 weeks. Surface electromyographic recordings were taken from each patient before the beginning of clinical therapy and after 6 weeks of wearing the splints. The data obtained were analyzed through paired sample t tests and Wilcoxon's signed rank tests. The results of the study were as follows: (1) the electromyographic activity of the two muscles during maximal biting was not markedly changed after the muscle relaxation splint was used; and (2) the changes observed in electromyographic activity of the involved and noninvolved sides were insignificant as well.

[Muscle relaxation by transcutaneous electric nerve stimulation (TENS) in bruxism. An electromyographic study]

In recent years transcutaneous electrical neuromuscular stimulation (TENS) has become increasingly more common in the treatment of functional diseases of the masticatory muscles and currently the practitioner can choose among a variety of stimulators. In an electromyographic study of 17 adults suffering from nocturnal bruxism and of a control group consisting of 18 adults without any functional disturbances of the masticatory muscles, the effect of this kind of neuromuscular stimulation on the temporal and masseter muscle was examined. The myoelectric signals were registered before and after TENS treatment in 3 different positions of the mandible. Each person was treated 3 times with both the Myo-Monitor (Myo-Tronics, Seattle) and the TNS SM2 MF stimulator (schwa-medico, Giessen). The different effects of continuous low frequency and intermittent high frequency muscular stimulation were studied simultaneously. Muscular activity was determined by computer aided integration of the electromyographically measured raw signals. A fourier analysis of the power spectrum yielded information on the frequency behavior of the studied muscles resulting from the TENS treatment. A statistical analysis of the results led to the following significant conclusions: 1. TENS treatment decreased the values of the registered integrated signals on all test persons, however, the treatment increased the median frequency and the mean power frequency (MPF). Since this effect is contrary to muscle fatigue, these electromyographic results can be interpreted as providing objective proof of a relaxation in the treated muscles. 2. The electromyographic changes after TENS treatment were similar when using either the Myo-Monitor or the TNS SM2 MF stimulator. In addition, the 2 different types of stimulation (high or low frequency) showed the same effects. 3. Compared to the persons in the control group, there was no significant increased muscular activity in patients with nocturnal bruxism. Following TENS treatment both groups showed the same alterations in the electromyograms. The results of the study provide further evidence that TENS treatment is an adequate supportive procedure in the treatment of nocturnal bruxism.

Treatment alternatives for patients with masticatory myofascial pain

Alternative therapies are used by many people, and the dental literature has reported that some alternative therapies are comparable to splint therapy in the effective treatment of masticatory myofascial pain. The authors review the efficacy of alternative therapies and discuss their clinical implications. This review is intended to help dental practitioners to select alternative therapies they can use with or instead of splint therapy for treating patients who have a primary diagnosis of myofascial pain.

Activity recognition in long-term electromyograms

Long-term electromyography with portable recorders allows the study of muscle activity in the natural environment to investigate whether muscle overuse or oral habits may contribute to initiate or perpetuate a myoarthropathy of the masticatory system. At present, little is known about the behaviour of masticatory muscles over long time periods. The aim of this preliminary study was to define parameters which allow the automatic recognition of different types of oral activities from the electromyogram form. A programme with functional and parafunctional activities was performed by four volunteers (total of 333 functional and 82 parafunctional recordings). Electromyograms of the masseter and temporal muscles were recorded by means of a self-developed portable intelligent solid state recorder. Signal mean level (mw) and dynamics (dw) within a sliding window were determined. Temporal muscle recordings allowed better discrimination between function and simulated parafunction. The average of mw for clenching was 51.4 +/- 3.5% and for tooth grinding 21.2 +/- 2% of the peak electromyogram value at maximum voluntary clench. At 0.96 s sliding window duration, clenching, tooth grinding and chewing signals had maximum separation, using dw/mw as parameters (average: 0.16 +/- 0.01 for clenching, 0.39 +/- 0.01 for teeth grinding and 0.88 +/- 0.01 for chewing).

Effects of splint therapy in TMJ dysfunction: a study using magnetic resonance imaging

This pilot study was undertaken to correlate clinical and MRI diagnoses in seven symptomatic TMJ dysfunction patients and to account, if possible, for the clinical improvement in the signs and symptoms after the use of a maxillary stabilizing splint. The symptomatic TMJs were evaluated by means of MRI prior to splint insertion. Sagittal open/closed, and coronal closed images were obtained with a 0.3 T Fonar MR Scanner. A follow-up MRI was taken after three months of splint therapy for the purposes of a comparative study. All subjects responded positively even at the early phase of splint treatment. By the end of the three month period, six subjects experienced full remission of pain in the TMJ and associated masticatory muscles with one subject experiencing only partial remission following therapy. Baseline MRI study revealed that only three subjects had anterior disc displacement while the other four subjects had normal disc/condyle relationships and morphology. In the follow-up MRI study, there were no signs of recapture of the three anteriorly displaced discs despite there being evidence of improved jaw movement and remission of pain symptoms. The use of MRI in this preliminary study indicates that some but not all TMJ pain dysfunction syndromes are caused by internal derangements of the joint. A larger MRI study using the same clinical parameters is indicated for future research.

Reliability of a portable electromyographic unit to measure bruxism

This study evaluated the effect of different rates of increase of occlusal force and of removal and replacement of the electromyographic electrodes on the amount of occlusal force needed to trigger a modified electromyographic measuring unit. Seven subjects placed the electrodes on the masseter area on one side, and bit ipsilaterally on a bite force transducer. The electromyographic recorder was adjusted to be triggered only when the subject clenched. Occlusal force was recorded simultaneously with triggering of the electromyographic recorder. The subjects performed two series of five repetitions of clenching at each of four different rates of increase of force, by visual feedback from a second oscilloscope until the electromyographic recorder was triggered, and an occlusal force measurement was made from the first oscilloscope. Repeated measures of ANOVA analysis revealed no statistically significant differences among the different rates of increase in occlusal force or between the two recording series. Interaction between the two factors also was not significant. The intraclass correlation coefficient was large and statistically significant, indicating that this device was reliable for this method.

Dental splint prescription patterns: a survey

A random sample of U.S. dentists was surveyed with a mailed questionnaire to determine the number of splints that they fabricated over the preceding year for bruxers, patients with myofascial pain-dysfunction syndrome and patients with TM joint pain. The results indicate that a significant number of dentists treat these disorders with dental splints. Estimates are provided for the dental profession's yearly splint output for each disorder.