Severe Bruxism/ Neuromuscular Dentistry/ Dental Sleep Medicine/ TrigeminoCardiac Reflex and SPG Blocks are all connected and part of the same system

Dr. Shapira TMJ 0 Comments

What is the common underlying link of all of these.  The Trigeminal Nerve and the Autonomic nerves of thee Sphenopalatine Ganglion.
Self-Administered SPG Blocks can improve many autonomic issues in patients.
This is the connection of TMJ disorders to problems with the gut.
The connection of Aiirway collapse secondary to dental issues has been well established.
Bruxism is far more than a habit it is part of a medical group of disordrs.
. 2018 Aug; 4(8): 329–331.
Published online 2018 May 18. doi:  [10.1016/j.hrcr.2017.06.013]
PMCID: PMC6092563
PMID: 30112280

Grinding to a halt: Stimulation of the trigeminal cardiac reflex from severe bruxism

Key Teaching Points

  • • The autonomic nervous system has an intricate relationship with the heart; severe vagal stimulation can produce bradycardia and asystole.
  • • The trigeminal cardiac reflex is a powerful brain stem reflex that can be associated with a sudden onset of parasympathetic dysrhythmia, sympathetic hypotension, or gastric hypermotility.
  • • Bruxism, which is reported in 8% of the population, can stimulate the trigeminal cardiac reflex and lead to profound vagal effects on the heart.


The trigeminal cardiac reflex (TCR) is a unique, powerful, and well-established neurocardiogenic reflex that is a result of stimulation along the path of the fifth cranial nerve (trigeminal nerve). It can produce adverse cardiorespiratory changes including hypotension, bradycardia, and asystole, as well as gastric consequences such as hypermotility. This reflex has been reported to occur in various surgical conditions, as well as in neurosurgical interventions.

Sleep bruxism, thought to be a more intense form of rhythmic masticatory muscle activity, has a prevalence of about 8% and has been explicitly linked to the TCR.We report a case of a young woman with severe bruxism who incited her TCR, which subsequently produced profound nocturnal pauses that ultimately required dual-chamber pacemaker implantation.

Case report

A 27-year-old woman presented with palpitations and syncope. Three years prior to presentation she developed nocturnal and early morning nausea and vomiting that would often wake her from sleep. She was noted to have a long-standing history of severe bruxism with physical signs on examination of significant attrition. This had persisted despite the use of a retainer and bite block. Evaluation with Holter monitoring revealed sinus bradycardia, intermittent second-degree type II atrioventricular (AV) block, and a pause of 8.6 seconds (Figure 1). Interestingly, the rhythm strips showed simultaneous effects on both the sinus and AV node, suggesting an autonomic etiology. Of note, these rhythm disturbances were principally nocturnal in nature. While she was wearing the Holter, the husband was awake and corroborated that she was having severe episodes of bruxism. Further cardiac evaluation was unrevealing, including a normal echocardiogram, cardiac magnetic resonance imaging, sleep study, and thorough autonomic testing. With her constellation of symptoms—severe bruxism, AV nodal block with cardiac pauses (that were predominantly nocturnal), and gastrointestinal symptoms—we diagnosed her with hypervagotonia from stimulation of the powerful TCR from severe bruxism (Figure 2). Out of concern for risk of cardiac death from these pauses without a stable ventricular escape, we elected to place a dual-chamber pacemaker for bradycardic prevention.

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Holter monitoring revealed sinus bradycardia, intermittent second-degree type II atrioventricular block, and a pause of 8.6 seconds

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Illustration of the trigeminal cardiac reflex. X = motor nucleus of the vagus nerve; ∗ = Gasserian ganglion; V = trigeminal nerve.


This case highlights the intricate and noteworthy relationship between the autonomic nervous system and the heart. Our patient developed high-grade AV block and syncope owing to significant and profound hypervagotonia. Based upon her evaluation and corroboration of these events by her husband, we deemed that her intense vagal stimulation was a consequence of her severe bruxism, which was eliciting the TCR.

The TCR (Figure 2) is a powerful brain stem reflex that can be associated with a sudden onset of parasympathetic dysrhythmia, sympathetic hypotension, or gastric hypermotility. The proposed mechanism of this reflex is stimulation of the sensory nerve endings of the trigeminal nerve (Figure 2, cranial nerve V), which sends signals via the Gasserian ganglion (Figure 2, indicated by asterisk) to the sensory nucleus of the trigeminal nerve (Figure 2 inset). The afferent pathway then continues along the short internuncial nerve fibers in the reticular formation to connect with the efferent pathway, the motor nucleus of the vagus nerve (Figure 2, cranial nerve X). The last part of the reflex is formed by cardioinhibitory efferent fibers, which connect the motor nucleus of the vagus nerve to the myocardium.

Bruxism is a common occurrence in the population (8%) and has been associated with alterations in the autonomic nervous system and stimulation of the TCR. The mechanism behind the TCR stimulation is felt to be 2-fold. Firstly, masticatory movements (rhythmic masticatory muscle activity) and secondly, teeth contact can stimulate mechanoreceptors in the periodontal tissue. The link between bruxism, TCR, and alteration in the autonomic nervous system is important to highlight as it is well established that the autonomic nervous system plays a critical role in the pathogenesis of various cardiac arrhythmias, particularly atrial fibrillation. Although not specifically related to our patient, the fact that bruxism is so common raises the potential role it could be contributing to autonomic drivers of atrial fibrillation, and this is something that requires further research examination.


When evaluating patients who present with symptoms of significant hypervagotonia, it is important to consider sleep-related causes, in particular sleep bruxism and its role in the TCR.


Dr DeSimone is supported by an NIH T32 training grant (HL 007111).


1. Reding G.R., Rubright W.C., Zimmerman S.O. Incidence of bruxism. J Dent Res. 1966;45:1198–1204. [PubMed]
2. Schames S.E., Schames J., Schames M., Chagall-Gungur S.S. Sleep bruxism, an autonomic self-regulating response by triggering the trigeminal cardiac reflex. J Calif Dent Assoc. 2012;40:670–671. 674–676. [PubMed]
3. Arasho B., Sandu N., Spiriev T., Prabhakar H., Schaller B. Management of the trigeminocardiac reflex: facts and own experience. Neurol India. 2009;57:375–380. [PubMed]
4. Gastaldo E., Quatrale R., Graziani A., Eleopra R., Tugnoli V., Tola M.R., Granieri E. The excitability of the trigeminal motor system in sleep bruxism: a transcranial magnetic stimulation and brainstem reflex study. J Orofac Pain. 2006;20:145–155. [PubMed]
5. Chowdhury T., Bindu B., Singh G.P., Schaller B. Sleep disorders: is the trigemino-cardiac reflex a missing link? Front Neurol. 2017;8:63. [PubMed]
6. Sjoholm T.T., Piha S.J., Lehtinen I. Cardiovascular autonomic control is disturbed in nocturnal teethgrinders. Clin Physiol. 1995;15:349–354. [PubMed]
7. Okada Y., Kamijo Y., Okazaki K., Masuki S., Goto M., Nose H. Pressor responses to isometric biting are evoked by somatosensory receptors in periodontal tissue in humans. J Appl Physiol. 2009;107:531–539. [PubMed]

TMJ Vision Problems

Dr. Shapira Chicago, Deerfield, Evanston, Highland Park, Kenilworth, Lake Bluff, Lake Forest, Libertyville, Lincolnshire, Mettawa, Morton Grove, Northbrook, Northfield, Skokie, Vernon Hills, Vision, Wilmette, Winnetka 51 Comments

The jawbone’s connected to … the eyes?

tmj-vision-problems-chicagoOf all of the problems that can be caused by disorders of the TMJ, eye strain or TMJ vision problems may seem to be the strangest. How can a joint that controls the jaw cause problems with your eyesight? Through muscles and nerves, your TMJ is wired to nearly everything else in your head, neck and face.

TMJ causes headaches, and headaches can, in turn, cause vision problems. Another factor is a nerve that is responsible for more than half of the total input to the brain: the trigeminal nerve. Understanding a bit about the trigeminal nerve will make it easy to see the connection between TMJ disorder and vision.

The trigeminal nerve has three branches:

  • Ophthalmic (pertaining to the eye)
  • Maxillary (pertaining to the upper jaw bone)
  • Mandibular (pertaining to the upper jaw bone)
  • The Sphenopalatine Ganglion is on the Maxillary Division of the Trigeminal Nerve and it carries Autonomic nerves, both Sympathetic and Parasympathetic to the Trigeminal Nerve.  These nerves travel throughout the trigeminal system and to the brain.  A simple Sphenopalatine Ganglion Block can give Amazing, often almost immediate relief of symptoms.  Dr Shapira teaches courses on blocking the Sphenopalatine Ganglion both nationally and internationally.  He is one of the only doctors who teaches “Self Administration of SPG Blocks” with cotton tipped nasal cannulas.
  • SPG Blocks can treat Migraines, Chronic Daily Headaches and many painful conditions of the Ears, Eyes, Sinus and Nasal regions.

Your TMJ: It’s got a lot of nerve

These three nerve braches make the connection between the jaw and the eyes rather clear. TMJ pain is transmitted through these nerve pathways, and it can result in pain in other parts of the face. Many TMJ patients experience disturbances in vision.

Other common complaints are:

Retro-orbital Pain or pain behind the eyes

  • pressure behind the eyes
  • blurry vision
  • watery eyes
  • eye strain
  • floaters (small moving spots that you see in your field of vision)
  • Droopy Eyelids
  • Many patients feel they have a vision problem because pain makes it difficult to read, especially small print or off a computer

Beware the domino effect

Our reaction to pain can often make the situation worse. When we feel the pain of a headache, jaw pain, neck pain or other pain related to TMJ, we unconsciously respond by positioning ourselves differently or using our muscles differently in an attempt to alleviate the pain.

Pain in the face or head can have a domino effect, with one issue leading to another through the trigeminal nerve or our own reactions to the pain.

Check your habits

tmj-habitsYour TMJ is an important – and potentially problematic – part of your body.

The two joints lie on either side of the head between the mandible; the lower jaw, and the temporal bone at the base of the skull. It’s what allows our jaws to open and close. Because using our jaws is involved in two of the primary functions of our lives: eating and speaking, the TM joints are susceptible to issues.

A TMJ disorder can be caused suddenly by an injury to the head or face, but more often, it builds up gradually. It can be due to our behavior or habits.

Some common habitual causes of TMJ disorder are:

  • Teeth clenching
  • Eating hard foods frequently or taking oversized bites
  • Poor posture

People who sing or speak for a living may be more likely to encounter TMJ issues. Anyone can develop TMJ problems, and in order to get rid of the pain, vision problems, or other issues caused by TMJ, the TMJ problem itself must be eliminated.

The field of TMJ and orofacial pain covers a wide variety of problems and differential diagnosis of orofacial pain is important.

Get relief from TMJ Vision Problems

TMJ is best treated with non-invasive methods that do not permanently change the structure of the jaw or teeth. Pain relievers can help, and there are jaw and posture exercises that can bring relief to TMJ sufferers.  If you are experiencing vision problems, headaches, jaw pain or facial pain, TMJ could be the cause.

To learn more about TMJ or to make a consultation appointment, contact our office.