A complete guide to bruxism and occlusion: a map of the domain, from the evolution of the definition and the limits of assessment through the evidence on consequences to occlusal splints and occlusal adjustment｜證據鏈

A complete guide to bruxism and occlusion: a map of the domain, from the evolution of the definition and the limits of assessment through the evidence on consequences to occlusal splints and occlusal adjustment｜證據鏈

F-Units (fact ledger)

F1 | The international consensus defines bruxism as a repetitive jaw-muscle activity characterised by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible, and distinguishes two circadian manifestations, the sleep type and the awake type

• source #: #01 | confidence: high | basis: clinical_guideline (international expert consensus statement, PMID 23121262) | geo: universal | period: J Oral Rehabil, 2013
• caveat: this is a written expert consensus and not the conclusion of an empirical trial; it is the 2013 version, whose addendum was revised in the 2025 version (see F3).

F2 | The 2018 assessment consensus holds that in otherwise healthy individuals bruxism should not be considered a disorder but a behaviour that may be a risk (or protective) factor for certain clinical consequences; and that standard cut-off points should not be used to establish its presence or absence

• source #: #02 | confidence: high | basis: clinical_guideline (PMID 29926505) | geo: universal | period: J Oral Rehabil, 2018
• caveat: the original describes itself as a 「work in progress」 report; the protective side of “risk (or protective) factor” is not developed in this article, because no downstream evidence was available to cite.

F3 | The 2025 international consensus meeting report removes the addendum “in otherwise healthy individuals” from the definitions and revises the grading system to rest on self-report / clinical examination / device-based assessment

• source #: #03 | confidence: high | basis: clinical_guideline (PMID 40312776; closed workshop at the 2024 IADR annual session) | geo: universal | period: J Oral Rehabil, 2025
• caveat: the purpose of that report is to clarify definitions and terminology; it is not an efficacy or management guideline and must not be cited as the basis of any management recommendation.

F4 | The prevalence of bruxism differs greatly with the method of measurement: the umbrella review records awake bruxism in adults at 22%–30%, sleep bruxism in adults at 1%–15% and sleep bruxism in children and adolescents at 3%–49%; the global review records sleep 21%, awake 23%, combined 22.22% and 43% among those determined by PSG; the meta-analysis of awake bruxism gives 15.44% (99% CI 10.81–20.72%)

• source #: #04 / #W7 / #14 | confidence: moderate | basis: peer_reviewed (PMID 30993738 / 39064299 / 37853263) | geo: universal | period: 2019 / 2024 / 2023
• caveat: the four sets of figures were measured in different ways; they cannot be compared with one another and cannot be averaged; in #14 no included study scored high across all nine JBI items; #W7 states of itself that it could not analyse Africa and Australia; the PublicationType index of #W7 is Review rather than Systematic Review, and this article reads it according to the systematic-review method it describes for itself, without claiming its index level.

F5 | The validity of self-reported bruxism against true sleep bruxism (as determined by PSG) is very low; PSG itself is extremely expensive and time-consuming

• source #: #W10 | confidence: moderate | basis: peer_reviewed (PMID 26010126) | geo: universal | period: J Oral Rehabil, 2015
• caveat: the sample was women with chronic myofascial temporomandibular disorders (124) and matched controls (46), so the population is limited to women and consists mainly of TMD patients, and must not be extrapolated to the general population as a whole; this entry supports only “self-report is not enough to replace instrumental determination”, and does not support “self-report is of no use at all”.

F6 | The factors consistently associated with bruxism include alcohol, caffeine, tobacco, some psychotropic medications, oesophageal acidification and second-hand smoke; the signs and symptoms of temporomandibular disorders present a plausible association

• source #: #04 | confidence: moderate | basis: peer_reviewed (umbrella review, PMID 30993738) | geo: universal | period: 2019
• caveat: this is a record of association, not causation, not behavioural advice and not medication instruction; the same review states of itself that associated factors and structural effects were considerably heterogeneous and inconsistent.

F7 | Sleep bruxism is more prevalent in several sleep-disorder populations than in the general population; sleep arousal may be a common associated factor; the specific mechanisms could not be identified

• source #: #W6 | confidence: moderate | basis: peer_reviewed (PMID 34879286) | geo: universal | period: Sleep Med, 2022
• caveat: this is a comparison of prevalence and an association and must not be read as causation or as an indication for screening; the original states plainly that the mechanisms could not be identified.

F8 | There seems to be an association between bruxism, temporomandibular disorders and psychological factors (stress / anxiety / depression), and how they interact remains to be researched

• source #: #W5 | confidence: low | basis: peer_reviewed (PMID 40127752) | geo: universal | period: J Dent, 2025
• caveat: a qualitative analysis of only 10 articles, searched in a single database (Web of Science), of observational studies; no causal claim may be made from it, nor may it be used to attribute cause in any individual case.

F9 | Tooth wear is a multifactorial phenomenon: bruxism (mechanical) and gastro-oesophageal reflux (chemical) may act in synergy

• source #: #13 | confidence: low | basis: peer_reviewed (PMID 35207380) | geo: universal | period: J Clin Med, 2022
• caveat: only 5 studies were included; the original wording is “could have associations and act in synergy”, which is at the level of a hypothesis; the PublicationType index of that paper is Review rather than Systematic Review.

F10 | No significant correlation was found between the frequency of bruxism events measured objectively by polysomnography and clinical tooth wear; tooth wear was likewise not associated with self-reported parafunctions

• source #: #11 | confidence: low | basis: peer_reviewed (primary cohort study, PMID 33474786) | geo: universal | period: J Oral Rehabil, 2021
• caveat: a single-centre primary study of 63 participants with a single night of recording, so its evidential weight is limited; it must not be escalated into “bruxism has been shown to be unrelated to tooth wear”. The background of the original likewise states that the two are considered related clinically but that strong evidence is lacking.

F11 | In a systematic review of 52 RCTs, no study used tooth wear in patients with bruxism as an outcome measure; it therefore cannot be determined whether splints reduce wear

• source #: #08 | confidence: high (as a record of an evidence gap) | basis: peer_reviewed (systematic review commissioned by NIHR HTA, PMID 32065109) | geo: universal | period: Health Technol Assess, 2020
• caveat: the search cut-off was 2018-10-01 and later evidence is not included; this entry is a record of an evidence gap, not a conclusion that “splints do not work”. The cost-effectiveness analysis of that review takes the perspective of the United Kingdom's NHS, which is local-system content, and this article cites none of its economic conclusions.

F12 | Restorations in bruxers have a comparatively higher failure rate (pooled OR per restoration 4.72, 95% CI 2.66–8.36; per patient 3.83); the causal relationship remains controversial in the literature

• source #: #W9 | confidence: low | basis: peer_reviewed (PMID 25726844) | geo: universal | period: Clin Implant Dent Relat Res, 2016
• caveat: the included studies are observational and the search cut-off was 2013-11; an odds ratio is not causation; the indications for and management of implants belong to P01 and are not developed here.

F13 | European expert consensus on severe tooth wear: restorative intervention is typically better delayed as long as possible; where intervention is needed a conservative, minimally invasive route complemented by preventive measures should be taken; the decision depends on severity, effects and the patient's wishes

• source #: #W3 | confidence: high | basis: clinical_guideline (PubMed PublicationType: Practice Guideline, PMID 28439579) | geo: universal | period: J Adhes Dent, 2017
• caveat: this is an expert consensus guideline, not a meta-analysis; this article cites only its statements of principle and none of its specific adhesive or procedural protocols.

F14 | Survival of anterior composite restorations in managing tooth wear: >90% at 2.5 years and about 50% at 5 years; strength of recommendation B; meta-analysis impossible because of heterogeneity; long-term data limited

• source #: #12 | confidence: low | basis: peer_reviewed (PMID 26440584) | geo: universal | period: J Oral Rehabil, 2016
• caveat: only 5 studies, 100 patients and 772 restorations; the 50% at 5 years is a reference for the order of magnitude, not an expectation for any individual tooth; the search cut-off was 2015.

F15 | The evidence on occlusal splints does not point one way: the umbrella review treats occlusal appliances as one of the few exceptions considered effective among therapies; the splint efficacy review holds the evidence insufficient to determine that they are superior to no treatment or other therapies; the NIHR review judges the quality of the evidence very low

• source #: #04 / #07 / #08 | confidence: moderate (for the fact of setting them side by side) / low (for any single-direction conclusion) | basis: peer_reviewed (PMID 30993738 / 33652054 / 32065109) | geo: universal | period: 2019 / 2021 / 2020
• caveat: the three asked different questions and must be set out together rather than selected between; every study in every comparison of #07 carried a medium to high risk of bias.

F16 | Comparison of splint types: the adjustable / full-occlusion biofeedback type was more effective in reducing sleep bruxism episodes and in improving self-reported symptoms; the impact of different appliances on electromyographic activity varies and potential adverse effects have to be considered individually; oral appliances showed no significant difference from other types of splint

• source #: #09 / #05 | confidence: low | basis: peer_reviewed (PMID 38182999 / 35356038) | geo: universal | period: BMC Oral Health, 2024 / Jpn Dent Sci Rev, 2022
• caveat: #09 included only 15 articles, some of them non-randomised; the PublicationType index of #05 is Review rather than Systematic Review, and this article reads it according to the systematic-review method it describes for itself, without claiming its index level; this article does not on that basis recommend any particular type of appliance.

F17 | The meta-analysis shows that soft and hard occlusal appliances alike did not influence the masticatory muscle activity and bite force of sleep bruxers, and only reduced tongue force; certainty very low

• source #: #10 | confidence: low (because the original rates the certainty as very low) | basis: peer_reviewed (PMID 38421263) | geo: universal | period: Eur J Oral Sci, 2024
• caveat: only 3 of the 12 studies were RCTs; “did not influence” is a pooled result and is not the same as the appliance having no clinical value, nor may it be read in reverse as the appliance being harmful.

F18 | Bruxism is positively associated with temporomandibular disorders: overall OR 2.25 (95% CI 1.94–2.56), awake type 2.51 (2.02–2.99), sleep type 2.06 (1.82–2.30)

• source #: #W4 | confidence: moderate | basis: peer_reviewed (PMID 37474733) | geo: universal | period: Evid Based Dent, 2023
• caveat: the included studies are observational (assessed with NOS), so an odds ratio is not causation; the concluding sentence of the original uses the wording “increases the likelihood of developing TMD in future”, and this article does not adopt that prospective phrasing.

F19 | Awake bruxism is positively associated with tension-type headache (OR 5.23, 95% CI 2.57–10.65); sleep bruxism shows no association with tension-type headache; the association with migraine is controversial

• source #: #W11 | confidence: low | basis: peer_reviewed (PMID 34129658) | geo: universal | period: J Oral Facial Pain Headache, 2021 Spring
• caveat: only 5 studies were included, meta-analysis was impossible and the certainty of the evidence was low to very low; the upper multiple stated in the concluding sentence of that abstract is inconsistent with the upper bound of the confidence interval it reports, and this article adopts the interval it reports throughout, not the multiple of the concluding sentence.

F20 | Occlusal interventions include splints and adjustments, occlusal adjustment being the grinding down of teeth to improve occlusion; Cochrane 2024 included 57 studies with 2,846 participants (the comparator throughout being splints), judged the certainty very low for all outcomes and found the evidence insufficient to reach conclusions

• source #: #W1 | confidence: high (as a record of the state of the evidence) | basis: peer_reviewed (Cochrane systematic review and meta-analysis, PMID 39282765) | geo: universal | period: Cochrane Database Syst Rev, 2024
• caveat: the subjects of that review were patients with temporomandibular disorders rather than patients with bruxism, and this article cites only its definition of occlusal adjustment and its overall judgement of the certainty of the evidence, without extrapolating its efficacy conclusions to the bruxism population.

F21 | The older Cochrane review “Occlusal adjustment for treating and preventing temporomandibular joint disorders” has had its 2016 version withdrawn: the reason being that it is out of date and does not meet current Cochrane methodological standards, and that it will be superseded by a new review of occlusal interventions

• source #: #W2 | confidence: high (for the fact of withdrawal itself) | basis: withdrawn_publication／not_evidence (PMID 26727292) | geo: universal | period: Cochrane Database Syst Rev, 2016
• caveat: this entry serves only to record an evidence gap, and its original conclusions may not serve as the basis of any medical claim; handled under the withdrawn-publication rule of ANK-DENTAL-SPEC. Its successor (#W1, PMID 39282765) was checked and has not been withdrawn.

F22 | The higher-level judgement on management: no single treatment is universally effective for all patients; a multidisciplinary approach combining therapies may yield better results; the effectiveness of appliances varies with design and material; longer and methodologically more rigorous studies are needed

• source #: #06 | confidence: moderate | basis: peer_reviewed (PMID 41366915, PROSPERO CRD42024597809) | geo: universal | period: Medicine (Baltimore), 2025
• caveat: the included studies comprise non-randomised designs and case series; the search window was 2019-10 to 2024-10, so earlier evidence is not included.

F23 | There are currently no official guidelines for the management of awake bruxism; behavioural approaches (biofeedback, guided music listening, habit reversal, reminder prompts, counselling with self-management) show a positive tendency, on limited evidence and without meta-analysis

• source #: #15 | confidence: low | basis: peer_reviewed (PMID 41735990, PROSPERO CRD42022351309) | geo: universal | period: BMC Oral Health, 2026
• caveat: only 9 studies with 165 participants, with varying risk of bias; the items listed in the original include “medication”, and this article neither cites nor develops any medication content.

F24 | Pharmacological and injection-type interventions are reported to produce significant reductions in specific bruxism parameters while side effects are also reported; recurrence or rebound after injection-type intervention needs more follow-up evidence

• source #: #05 / #W8 | confidence: low | basis: peer_reviewed (PMID 35356038 / 34955330) | geo: universal | period: 2022 / Br J Oral Maxillofac Surg, 2022
• caveat: under the Medical Care Act rule that prescription medicines may not be advertised to the public, this article deliberately lists the name of no medicine or injectable product and makes no statement about the direction of their effect; this entry records only the state of the evidence, that this route has been studied and that long-term data are insufficient, asserting neither that it works nor that it does not. #W8 had only 6 studies with 148 participants.

F25 | The diagnostic criteria for sleep bruxism diverge conceptually between dentistry and sleep medicine; the AASM's 2023 ICSD-3-TR provides a standardised framework for medical settings, but its adaptation to dental contexts remains complex

• source #: #16 | confidence: moderate | basis: peer_reviewed (interpretive review, PMID 41192107) | geo: universal | period: Sleep Med, 2026
• caveat: the original ICSD-3-TR manual is not open access and was not retrieved on this machine, so this article cites only the abstract content of this interpretive paper and may not describe it as the AASM's own statement.

Compliance note

• This article is health education and a compilation of medical developments. It is general oral-health education information, does not solicit medical business, does not constitute medical advertising, and does not constitute diagnostic or treatment advice.
• This article provides no amount, fee or coverage information, recommends no healthcare institution, clinician, brand or product, contains no identifiable individual case, and contains no third party's subjective commentary on a course of treatment.
• This article lists the name of no prescription medicine or injectable product, makes no statement about treatment effect, and contains no medication, dose or procedural instruction; the relevant citations present only the state of the evidence and its limits.
• This article provides no splint wearing time or length of treatment, and no self-assessment scale or self-management scheme of any kind.
• All the data in this article are research results at population level. Actual treatment approaches and outcomes vary from person to person and must be assessed by a dentist before any decision.
• This article is a draft. It has not passed the publication gate, the four language versions are not yet complete, and it is for internal review only.

Source list

Date of access / live verification: 2026-08-06 (all sources verified live on the same day via curl / PubMed E-utilities, HTTP 200, with verbatim spans passing programmatic comparison in Python)

Pre-verified sources from the anchor file (`ida-pillars/anchors/P18-anchors.md`)

Statement in section 0 of the anchor file: the official_statement tier is absent for this field (MedlinePlus was checked live and has no dedicated bruxism page, the hit being the generic Tooth Disorders overview alone), so the higher-authority tier falls substantively to clinical_guideline; under the owner's 2026-08-06 decision that this whole line is global, Taiwanese regulation, insurance and health-authority content serves as the basis of no medical or system claim in this article, and local-system material is uniformly linked downstream to the corresponding TW canonical card and to P12.

WRITER-ADDED SOURCES (added by this article, with live verification evidence)

Reason for adding: the anchor file covers four patient questions (what to do about grinding in sleep / how long a splint has to be worn / does bruxism wear teeth out / jaw soreness on waking), but the scope of this article also includes (1) the conservative principle for occlusal adjustment (the anchor file holds no source on occlusal adjustment at all), (2) the quantitative association needed for the boundary with TMD, (3) the psychological-factor evidence on awake bruxism and stress, (4) sleep comorbidities on the aetiological side, (5) a second independent set of prevalence measurements, (6) the validity of self-reported assessment, (7) guidance on the conservative principle for managing wear, and (8) quantitative data on headache and on consequences for restorations. All 11 entries below were independently verified live on this machine with curl (HTTP 200) and passed programmatic verbatim comparison; the anchor file was not modified.