Occlusal splints for treating sleep bruxism (tooth grinding)
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
The purpose of this study is to evaluate the effectiveness of occlusal splints for the treatment of sleep bruxism with alternative interventions, placebo or no treatment.
Background
According to the International Classification of Sleep Disorders (ICSD‐2) (AASD 2005), sleep related bruxism is an oral activity characterized by teeth grinding or clenching during sleep, it is usually associated with sleep arousals, and it is usually accompanied by sounds (Bader 2000). Sleep bruxism is characterized by several signs and symptoms. Among the signs are abnormal tooth wear, fractured teeth, tongue indentation, polygraphic observation of jaw muscle activity with audible teeth grinding sounds, masseter muscle hypertrophy, facial pain, temporomandibular joint tenderness or pain or digital palpation, reduction in salivary flow, lip or cheek biting, and burning tongue with concomitant oral habits. Symptoms include teeth grinding sounds during sleep related by partner, jaw muscle discomfort with or without pain, headache, teeth hypersensitivity, stress and anxiety (AASD 2005; Okeson 1996). Severe sleep related bruxism may also result in sleep disruption which has implications not only to the patient, but also to the bed partner, because the sounds resulted by the teeth friction are usually perceived as being unpleasant and can be quite loud and disturbing.
Bruxism has been classified into: primary (idiopatic) or secondary (iatrogenic). Primary bruxism includes clenching and sleep bruxism and is not related to any medical condition, while secondary bruxism is associated with medical conditions (e.g. neurologic, psychiatric, sleep disorders medication) that may exaggerate primary bruxism (Lavigne 2000). Bruxism can occur when awake, a semi‐voluntary clenching activity of the jaw rarely associated with sounds, or when asleep. It is a different disorder and not known to be associated with sleep bruxism.
Sleep bruxism starts at 1 year of age, soon after the eruption of the deciduous incisors. Its prevalence in children ranges from 14% to 20% (Abe 1966; Widmalm 1995).
Frequently it appears in adolescence (Partinen 1994), with a prevalence of 13% in 18 to 29‐year olds. In adults, it is 8% considering the occurrence of teeth grinding during sleep at least weekly, decreasing with age (Lavigne 1994), up to 3% in individuals over 60 years (Ohayon 2001). There are no reported sex differences for sleep related bruxism (Glaros 1981; Lavigne 1994; Melis 2003). No genetic markers have been found for the transmission of this condition. However, 21% to 50% of patients who grind their teeth asleep have a direct family member who ground his or her teeth in childhood (Abe 1966).
Currently the central regulation has been the focus of study in bruxism (Lobbezoo 2001). Several risk factors have been linked to sleep bruxism such as tobacco, drugs, alcohol, psychiatric disorders, sleep disorders, anxiety, stress (Ohayon 2001), orofacial pain, joint sound or lock at the temporomandibular.
Polysomnography is useful in the differential diagnosis of sleep bruxism, along with other disturbances: obstructive sleep apnoea, periodic leg movements, REM sleep behaviour disorder, etc. (Lavigne 2000). A diagnosis of sleep related bruxism is given in the presence of at least four episodes per hour of sleep or 25 individual muscle bursts per hour of sleep and a minimum of two audible tooth‐grinding episodes per sleep recording session in the absence of associated abnormal electroencephalogram (EEG) activity (Lavigne 1996). Polysomnographic recordings must include additional electromyogram (EMG) derivations, surface electrodes placed over bilateral masseters, temporal muscles, sometimes frontal muscles, and audio‐video recordings in order to confirm the nature of the sounds (e.g. grinding, snoring) and type of movements (e.g. swallowing, myoclonus, body rocking) (Lavigne 1996). Polysomnography may be recommended to confirm the disorder or to rule out associated respiratory disturbance, RDB, night terrors, facio‐mandibular, myoclonus, or epilepsy. The sensitivity of polysomnographic study in detecting severe cases of sleep related bruxism is moderate to high.
Many lines of treatment for sleep related bruxism have been proposed such as pharmacological, psychological, and dental. Pharmacological treatments include various drugs such as benzodiazepines, anticonvulsants, beta blockers, dopamine agents, antidepressants, muscular relaxants, and others. Patients with severe bruxism have been administered local injections of botulinum toxin (BTX type A) for the elimination of symptoms (Tan 2000). However, little is known about its effectiveness, pharmacological safety, and the follow up of the drug for a long period of time (Lavigne 2000). The psychological treatment is behaviour therapy based on sleep hygiene, relaxation to control stress, psychotherapy, hypnosis, and biofeedback (Lavigne 2000). Dental treatments for bruxism include occlusion adjustment, tooth surface restoration, and orthodontic treatment. These interventions are extensive and irreversible and these are not recommended in most cases (Clark 1985; Okeson 1996). Occlusal appliances such as a soft mouth guard or hard occlusal stabilization splint are reversible interventions. Soft mouth guards are usually recommended for short‐term use because degradation can occur rapidly (Lavigne 2000). Occlusal splints seem to reduce teeth grinding (Dubé2004), muscular activities, and myofacial pains (Raphael 2003). Conversely, others have found an increase in muscle activity in 20% of hard splint users and in 50% of soft splint users (Okeson 1987). The cases presented in the literature seem to indicate a need to evaluate the use of occlusal splints for the treatment of sleep bruxism with alternative interventions.
Objectives
The purpose of this study is to evaluate the effectiveness of occlusal splints for the treatment of sleep bruxism with alternative interventions, placebo or no treatment.
Methods
Criteria for considering studies for this review
Types of studies
We aim to identify all randomised controlled trials (RCTs), in which occlusal splint is compared concurrently to placebo, no treatment, pharmacological interventions, any other occlusal appliances or behaviour therapy. Trials using quasi‐random methods of allocation (such as alternation, date of birth, record number) will be included and subject to a sensitivity analysis.
Types of participants
All participants with sleep bruxism (tooth grinding or clenching). Children and adults: limits greater than 1 year old.
Diagnostic criteria: clinical and/or polysomnographic.
Clinical diagnosis
The participant has a complaint of tooth grinding or tooth clenching during sleep and one or more of the following: abnormal tooth wear, tooth grinding sounds during sleep and jaw muscle discomfort.
Polysomnographic monitoring
Polysomnographic monitoring demonstrates both of the following: jaw muscle activity during the sleep period and absence of associated epileptic activity.
Polysomnographic diagnostic cut‐off criteria: (1) more than 4 bruxism episodes per hour, (2) more than 6 bruxism bursts per episode and/or 25 bruxism bursts per hour of sleep, and (3) at least 2 episodes with grinding sounds (Lavigne 1996).
Exclusion criteria: only outcome pain will not be considered when participants use co‐interventions (occlusal splint and analgesics).
Participants with comorbidity like movement disorders, and neurological and psychiatrical diseases.
Types of interventions
Occlusal splint compared with any of the following groups.
Placebo.
No treatment.
Other types of appliances (mouth guard, bite splint, splint, anterior tooth device, dental occlusal).
Pharmacological interventions such as benzodiazepine, anticonvulsants, beta blockers, dopamine agents, antidepressants, botulin toxin A and B, analgesics and others .
Behaviour therapy such as sleep hygiene, relaxation to control of stress, psychotherapy, hypnosis and biofeedback.
Types of outcome measures
Primary outcome
Indexes of bruxism motor activity through EMG masseter muscle associated with polysomnographic audio‐video recordings: frequency of sleep bruxism episodes per hour of sleep (at least four episodes) and number of episodes with grinding noise (minimum of two).
Secondary outcomes
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Tooth wear (using a ordinal scale)
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Tooth restoration failure
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Quality of life
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Adherence
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Adverse events
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Temporomandibular joint pain (using a Visual Analog Scale)
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Assessment of clicking (joint sound) (yes or no)
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Assessment of jaw movement limitation
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Assessment of myofacial pain (using a Visual Analog Scale)
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Assessment of headaches(yes or no )
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Stress level: measures (using a validated scale)
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Mood factors (using a validated scale)
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Anxiety (using a validated scale)
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Depression (using a validated scale)
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Sleep variables: REM sleep latency, efficiency, arousals index, stages, sleep latency, wake after sleep onset, total sleep time
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Masseteric EMG activity
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Apnoea‐hypopnoea index.
Search methods for identification of studies
Studies will be searched independently of language and source of information.
Electronic search
For the identification of studies included or considered for this review, detailed search strategies will be developed for each database. These will be based upon the search strategy developed for MEDLINE but revised appropriately for each database to take into account differences in controlled vocabulary and syntax rules.
The search strategy will combine the subject search with phases 1 and 2 of the Cochrane Sensitive Search Strategy for RCTs (as published in Appendix 5b in the Cochrane Handbook for Systematic Reviews of Interventions 4.2.5 updated May 2005).
The subject search will use a combination of controlled vocabulary and free text terms based on the search strategy for searching MEDLINE via PubMed presented below:
#1 bruxism*
#2 bruxist*
#3 bruxe*
#4 teeth AND grind*
#5 teeth AND clench*
#6 tooth AND grind*
#7 tooth AND clench*
#8 #1 OR #2 OR #3 OR #4 OR #5 OR #6 OR #7
#9 occlusal AND splint*
#10 splint*
#11 appliance*
#12 bite‐splint*
#13 bite‐plate*
#14 bite AND splint*
#15 bite AND plate*
#16 #9 OR #10 OR #11 OR #12 OR #13 OR #14 OR #15
#17 #8 AND #16
Databases to be searched
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Cochrane Oral Health Group Trials Register
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The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, current issue)
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MEDLINE (1966 to present)
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EMBASE (1980 to present)
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LILACS (1982 to present)
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DISSERTATION, Theses and Abstracts (1981 to present)
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Biblioteca Brasileira de Odontologia (1982 to present).
Cross‐checking references
References from original papers and abstracts, reviews, systematic reviews and meta‐analysis will be checked to identify any additional studies.
Personal communication
Authors of the included studies will be contacted to ask if they have, or know of, any relevant unpublished material.
Handsearching
Abstracts from sleep medicine meetings (APSS ‐ Associated Professional Sleep Societies).
Abstracts from odontology meetings (Academy of Dental Sleep Medicine).
Data collection and analysis
S tudy selection
All potentially relevant articles and reports will be assessed using a previously prepared inclusion criteria form. Two authors (Cristiane Macedo (CRM), Marco Machado (MAM)) will initially assess the relevance of each article independently and in duplicate. Citation information will not be masked. Disagreements will be resolved by third review (Ademir Silva (ABS) or Gilmar Prado (GFP)). The authors of the trials will be contacted for additional information, if necessary.
Data extraction
The data will be extracted by authors (CRM, MAM) and in case of discrepancy, a third author (ABS or GFP) will be consulted for further discussion and reliability. Agreement between authors will be assessed using Kappa statistics.
Data collection will be undertaken according to the following criteria using specially designed data extraction forms.
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Study methods: randomisation procedure, method of allocation, blindness, design, duration.
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Participants: country of origin, sample size, age, gender, diagnosis criteria, history, setting, participants after randomisation and proportion of follow‐up losses.
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Intervention: occlusal splint.
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Control: placebo, other types of appliances, drugs, behaviour therapy
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Outcomes: primary and secondary outcomes mentioned in the section of outcome measures.
This information will be used to help us assess heterogeneity and external validity of the trials.
Quality assessment
The methodological quality of included studies will be assessed using the following criteria, described in the Cochrane Handbook of Systematic Reviews of Interventions.
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Randomisation: graded as adequate (A), unclear (B), inadequate (C). Adequate (A) will include any one of the following methods of randomisation: computer generated or table of random numbers, drawing of lots, coin‐toss, shuffling cards or throw of a dice. Inadequate method of randomisation (C) utilising any of the following: case record number, date of birth or alternate numbers will be judged as inadequate.
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Concealment of allocation: graded as adequate (A), unclear (B), inadequate (C) or concealment not used (D). Adequate (A) methods of allocation concealment would include either central randomisation or sequentially numbered sealed opaque envelopes. This criterion will be considered inadequate (C) if there is an open allocation sequence and the participants and trialists can foresee the upcoming assignment.
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Blinding of outcomes assessment: whether persons assessing the outcome of care were aware of which treatment the participant received, will be graded as yes, no and unclear (detection bias).
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Handling of withdrawals and losses ‐ was there a clear description given of the difference between the two groups of losses to follow up which will be graded as yes (A), unclear (B) and no (C) (attrition bias).
Data analysis
For dichotomous outcomes, the estimate of effect of an intervention will be expressed as risk ratios together with 95% confidence intervals. For continuous outcomes, weighted mean difference (WMD) to compare groups and standard deviation will be used to summarise the data for each group. Using the random‐effects model.
Data synthesis
Clinical heterogeneity will be assessed by examining the types of participants, interventions and outcomes in each study. Meta‐analysis will only be used when studies are of similar comparisons reporting comparable outcome measures in similar participants. Weighted mean differences will be combined for continuous data and risk ratios for dichotomous data. The significance of any discrepancies in the estimates of the treatment effects from the different trials will be assessed by means of Cochran's test for heterogeneity. Inconsistency among the pooled estimates will be quantified using the I2 statistic.
Sensitivity analyses will be undertaken to examine the effect of randomisation, allocation concealment and blind outcome assessment on the overall estimates of effect.
If there is an adequate number of studies, quasi‐randomised studies will be analysed separately from the randomised ones in a sensitivity analysis.
In a attempt to assess publication bias, data will be plotted onto a funnel plot graph (trial effect versus trial size).
