Why Do Patients Still Grind and Clench After Neuromuscular Treatment?

The question

Why do some patients keep grinding and clenching even after they have been placed in a neuromuscular position?

The usual explanation describes what the nervous system is doing at the moment of grinding or clenching. Grinding is the lateral effort to move an obstructing tooth out of the way. Clenching is a vertical, centrally mediated behaviour, and certain medications can bring it on. There is truth in each of those observations. But they describe the end of a chain, not where it begins.

The real question is not what the nervous system is doing, but what is driving it. What is causing the grinding? What is causing the clenching?

GNM starts further back.

Part 1 — It starts at the neck

The mandible doesn’t hang alone. It is tied to the posturing muscles of the neck and the back of the head. When the occipital and cervical muscles are not neutralized, the jaw is pulled into a strain relationship contributing to occlusal grinding, abnormal forces, wear, tooth breakage, abfractions, gum recession, bone loss, tooth mobility and eventual loss.

There is a well-described anatomical reason this happens. Sensory input from the trigeminal system (V3), which serves the jaw muscles, and from the upper cervical nerves converges on the same relay region in the brainstem, the trigeminocervical complex. Neck strain and jaw strain are not separate conversations; they arrive at the same switchboard. (Bartsch & Goadsby 2003) And the jaw muscles’ own position sense travels through the mesencephalic nucleus, which sits in the midbrain itself. (Lazarov 2007; Yoshida et al. 2017)

This is why the J5 Dental TENS protocol pulses both the A group (over the coronoid notches and the back of the neck) and the B group (lower neck and the trapezius trigger points). The neck is relaxed alongside the jaw because it is part of the same system. It’s also why the K7 monitors the cervical muscles alongside the temporalis, masseter and digastric, before and after TENS.

Part 2 — The mandible, the interferences, and the grind

Grinding is not random. It is the mandible searching for a neutral (homeostatic/isotonic) – occlusal stable position.

“Grinding naturally occurs when teeth are not coincident with the optimized trajectory. Optimizing means where the muscles are in their homeostatic isotonic relationship.”

A neuromuscular position can be at a rest position and on a closure path and still be wrong in the other dimensions. The mandible moves in six: pitch, yaw, roll, lateral, frontal, and antero-posterior. If the teeth don’t all meet in harmony with the optimized myotrajectory in those six dimensions simultaneously, the lateral guidance still carries occlusal interferences. The body does what it has always done with an interference: it tries to grind it away.

So a patient who still grinds after neuromuscular treatment is not evidence that occlusion doesn’t matter. It is evidence that the occlusion is not physiologically finished in those other dimensions. The neuromuscular position may be right, but the guidance and other dimensions aren’t yet there.

That is why GNM treatment doesn’t stop at the myo-centric position in 3 dimensions:

• The displaced disc is reduced and the condyle-disc relationship optimized, so the muscles, including the lateral pterygoid and laryngopharyngeal muscles, can calm down.
• With the muscles quiet, the patient reaches a much more stable centric terminal contact.
• Only then are the occlusal adjustments carried out: lateral interferences removed, anterior disclusion established, and no posterior interferences left to drive clenching, grinding, and facial pain.

Part 3 — Clenching: what feeds the central nervous system?

Centrally mediated tells us where the signal is processed. The next question is what drives it.

“But what’s causing the midbrain issues, if it at all? What’s causing it to create?”

The muscles of the back form a continuous chain: from the sacrum, pelvis and ilium, up the iliocostalis and the back muscles, through the cervical neck, to the occiput and C1–C2. When the lower end of that chain is out of balance and the upper end isn’t neutralized, the strain travels up to the mandible. The result is clenching.

“From my experience, when these issues are neutralized, my patients amazingly then begin to say, I don’t clench anymore, or I don’t grind anymore.”

A central explanation and a structural one are not competing ideas. The nervous system processes what it receives. Change what it receives (the bite, the joint posture, the neck posture, the pelvis imbalance) and what it sends back to the jaw muscles changes too.

Part 4 — Medications and airway: real, but not the whole story

Two other drivers are real, and GNM screens for both.

Medications. Certain antidepressants, especially SSRIs, and stimulants are known to bring on clenching. When a medication is driving the clenching, the dentist should inform the patient to check with their prescribing physician to see whether to adjust the dose, switch the medication, or add another medication to counter the clenching. Published cases show the clenching often resolves when this is done. (Garrett & Hawley 2018)

Sleep apnea. Obstructive sleep apnea is a medical condition with serious cardiovascular and neurological consequences. It must be diagnosed by a sleep medicine physician, usually with an overnight sleep study, and treated accordingly.

In some patients, the jaw activity of sleep is tied to breathing. When the airway narrows or closes during sleep, the brain answers with a micro-arousal: a few seconds of lighter sleep, with a jump in brain activity and heart rate. Sleep studies show that grinding episodes, recorded as rhythmic masticatory muscle activity, typically follow this sequence: the brain stirs first, the heart rate rises next, and the jaw muscles fire last. (Kato et al. 2001) In patients with sleep apnea, most grinding events come shortly after a breathing event, not before it. (Saito et al. 2013)

In sleep medicine terms, this jaw activity is centrally driven: it starts in the brain’s arousal response, not in the teeth. But here too the question is what keeps the system under strain, and whether the jaw’s position and the muscles around the airway are part of it.

But airway is not the answer to everything. When the bite, the joint, and the postural chain have never been examined, the clenching and grinding remain. The temptation is to reach for something that can be done to the tissue instead.

Part 5 — Before the laser

Lasers are now being used to shrink and tighten the soft palate and uvula, mainly as a snoring treatment. Surgical reshaping of the palate for snoring is not new, and the earlier experience is worth remembering: improvements often faded, and sleep medicine advised against using it as a sleep apnea treatment. (Littner et al. 2001)

There is a more basic concern. A snore is an alarm. Quieting it without a sleep study can silence the one sign that sends a patient to be tested for apnea. And if an unbalanced jaw position or muscle strain is contributing to the problem, shrinking tissue doesn’t touch it.

The order matters: find what is driving the clenching and grinding before cutting tissue or adding medication.