Bruxism Management
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Direct answer
Listen for the grind before you search for the wear: bruxism is defined by international consensus as repetitive jaw-muscle activity — clenching or grinding — that is either sleep bruxism or awake bruxism, and it is graded as possible (reported), probable (report plus clinical signs) and definite (which requires polysomnographic and audio recording). Its management is conservative and behavioural first — habit awareness, sleep hygiene, stress management — protected by a full-arch stabilisation splint (Michigan splint) that shields the dentition, with botulinum toxin considered only for severe refractory cases. The one inviolable rule: never perform irreversible occlusal adjustment to "treat" bruxism, because occlusion is no longer considered its cause.
What you must remember
- Consensus grading: possible bruxism (self- or partner-reported grinding), probable bruxism (report plus clinical signs such as wear facets or masseter hypertrophy), definite bruxism (polysomnography with audio-video confirmation).
- Clinical signs: matching wear facets on opposing teeth, masseter hypertrophy (a "square" face), morning jaw tightness or headache, fractured cusps and restorations, cheek ridging (linea alba buccarum) and a scalloped tongue border.
- Current understanding of aetiology is central, not peripheral: sleep bruxism is associated with sleep arousals, stress, smoking, alcohol, caffeine and certain drugs (SSRIs, stimulants), and it frequently accompanies obstructive sleep apnoea — it is not caused by a "high spot" in the occlusion.
- Consequences: attrition with dentine exposure and sensitivity, cracked tooth syndrome, restorative failure, and muscle pain; the joint itself is implicated far less often than the muscles.
- First line: explanation, awake-habit reversal (lip seal, tongue-to-palate rest position, "lips together, teeth apart"), sleep hygiene (no alcohol or caffeine late, regular hours), stress reduction.
- Stabilisation (Michigan) splint: a flat-plane, full-arch hard acrylic appliance covering the maxillary teeth — it protects teeth and restorations and reduces muscle pain in many patients, though it does not abolish the behaviour itself.
- The anterior-only NTI-type splint is used selectively and with supervision; botulinum toxin into the masseters is reserved for severe, refractory, destructive cases.
- Sleep bruxism with snoring, witnessed apnoeas or daytime somnolence warrants a sleep-medicine referral, since treating the apnoea often reduces the bruxism.
Working through a grinder's plan
A 38-year-old banker presents because his partner is kept awake by nightly grinding; he wakes with tight, tired jaw muscles, and both masseters are visibly hypertrophic. Intraorally, generalised attrition has flattened the incisal edges, opposing wear facets interlock precisely, both cheeks show linea alba, and the tongue border is scalloped. Applying the consensus grading: report plus signs equals probable sleep bruxism — the defensible clinical ceiling without sleep-laboratory confirmation.
The plan builds in layers. First, screen the differential: erosion (dietary or reflux) is excluded by pattern — erosion cups the incisal edges and leaves restorations standing proud, whereas attrition leaves flat, matching facets. Second, screen for sleep-disordered breathing: he snores loudly, so a STOP-type questionnaire flags referral to sleep medicine, where treating any apnoea may reduce the nocturnal activity. Third, protect the dentition with a maxillary stabilisation splint worn nightly and reviewed. Fourth, address behaviour: awake-habit awareness, caffeine after noon cut out, short-term NSAIDs for the myalgic phase. Fifth, restore the worn dentition only after months of splint stability, because restorations placed into an active grinding habit fail.
Notice what is absent: occlusal equilibration. Grinding down "high spots" to cure bruxism fails the evidence, removes tooth structure irreversibly, and remains a standard viva wrong answer.
Where students slip
The commonest error is diagnosis by wear alone: attrition facets prove past wear, not present bruxism, and erosion-abrasion can masquerade as grinding — the history (partner's report, morning symptoms) is the discriminator, which is exactly why the consensus grading separates possible from probable. The second is overclaiming for the splint: the Michigan splint protects and often reduces muscle pain, but it does not stop the parafunction, and telling the patient "this cures grinding" stores up disappointment. Third is forgetting the sleep apnoea link — a heavy snorer with nocturnal bruxism needs a sleep study, not a thicker splint. And the classic trap: the patient who started grinding after an SSRI dose increase — drug-associated bruxism is managed with the prescriber, not by dental procedures.
Frequently asked questions
How are possible, probable and definite bruxism defined?
Possible bruxism is based on report of grinding or clenching; probable adds clinical signs; definite requires instrumental confirmation by polysomnography with audio-video recording.
What does a Michigan splint actually achieve?
A flat-plane, full-arch hard splint protects teeth and restorations from wear, redistributes forces, and frequently reduces associated muscle pain, but it does not eliminate the underlying parafunctional behaviour.
Why is occlusal adjustment not a treatment for bruxism?
Bruxism is driven by central factors — sleep arousals, stress, neurotransmitters — rather than by occlusal discrepancies, and irreversible equilibration removes sound tooth structure without stopping the behaviour.
When is botulinum toxin used for bruxism?
Only in severe, refractory cases with destructive wear or disabling muscle symptoms, injected into the masseters by trained specialists, with repeated dosing and realistic counselling about effect duration.