A patient sits in your chair with a cracked molar, a worn-down smile, and a night guard they’ve already replaced twice. The reflex is understandable: make another appliance and move on. But the appliance protects the teeth without ever answering the more important question — why is this patient clenching or grinding in the first place?
Bruxism is not rare. Recent data suggest clenching is reported by roughly one in four adults and bruxism by about one in five. General dentists see the consequences constantly: fractured crowns, failed veneers, masseter hypertrophy, and appliances worn straight through. Yet bruxism sits at the crossroads of restorative dentistry, sleep medicine, behavioral health, and pharmacology. Treating only the damage means treating only half the patient.
Clenching and Grinding Are Not the Same Thing
Clinicians often use the terms interchangeably, but they behave differently. Clenching is sustained, forceful tooth contact with little jaw movement — think of it as squeezing. It tends to happen during the day, during stress, concentration, driving, or working at a computer. Grinding involves movement, side to side or front to back — think of it as rubbing — and is often a sleep-related behavior tied to central nervous system activity and micro-arousals. Tooth wear alone doesn’t prove active bruxism, either. Wear can be historical. The real questions are whether it’s progressing, whether new restorations are failing, and whether the patient wakes with symptoms.
Start With Investigation, Not the Appliance
The answer is frequently not in the occlusion. It’s in the medical history, the medication list, the coffee cup, or the sleep pattern. Five areas of history do most of the work: medical, medication, social, sleep, and dental.
Two hidden categories deserve special attention. The first is prescription medications. Antidepressant-associated bruxism — particularly with SSRIs and SNRIs — is underrecognized, likely through altered serotonin–dopamine balance affecting motor control. ADHD stimulants can do the same. The clinical pearl is timing: did the clenching begin after a medication started, or worsen after a dose increase? We never tell a patient to stop a medication. We recognize the pattern and coordinate with the prescribing physician.
The second is stimulants and substances patients don’t think to mention. Caffeine from coffee, energy drinks, and pre-workout supplements can lower the threshold for clenching. Nicotine and alcohol belong here too, especially close to bedtime. Among recreational substances, methamphetamine, cocaine, and MDMA carry the strongest associations with jaw clenching; cannabis evidence is more mixed. The way we ask matters — “walk me through a typical day” yields far more than “do you use drugs?”
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Don’t Let Stress Become a Shortcut
Stress is a genuine contributor, but it can become the only explanation offered — and that’s the trap. A patient may be stressed and drinking 600 mg of caffeine a day, taking an SSRI, using nicotine pouches, and sleeping poorly. Occlusion matters for restorative planning, but bruxism is not simply an occlusal disease. This is also why general dentists should screen for sleep-disordered breathing: bruxism and obstructive sleep apnea can coexist. Snoring, morning headaches, witnessed apneas, and daytime sleepiness are reasons to refer, not to diagnose OSA from tooth wear.
Five Questions That Change the Conversation
If a busy GP remembers only one thing, remember to ask: Have you started, stopped, or changed any medications recently? How much caffeine do you consume daily? Do you use nicotine, cannabis, or recreational substances? Do you snore or wake up tired or with a headache? Have you broken teeth or gone through multiple night guards?
Those five questions move the dentist from treating damage to identifying the driver. The night guard still has its place — but a night guard without a diagnosis is incomplete care. Identifying the cause is just as important as protecting against the consequence.
Are you interested in a variety of issues focused on orofacial pain, medicine and sleep disorders? Consider enrolling in the Herman Ostrow School of Dentistry of USC’s online, competency-based certificate or master’s program in Orofacial Pain and Oral Medicine.
