TMJ & Migraine: Are you clenching your way to a migraine?
Based on ongoing discussion in the Migraine.com Community, we've invited James P. Boyd, DDS to share his thoughts on TMJ & migraine. There are many theories which apply to migraine pathogenesis & treatment, the article below highlights opinions expressed by Dr. Boyd. Do not stop, start or change any treatment program without first discussing the benefits and risks with a healthcare professional.
What is temporo mandibular joint (TMJ)?
The term TMJ, or Temporo Mandibular Joint, refers to the hinge joint between your jaw and skull. At one time, the dental industry assumed that disorders of this joint were a cause of people’s head and neck symptoms. However, no study has ever shown a causative connection between the condition of one’s TM joint and their symptoms or lack of symptoms!
What is TMJ occlusion?
When discussing your signs and symptoms with a dentist, you’ll often hear him refer to “the occlusion” as an important component of your condition. In the dental world, the occlusion refers to the scheme in which your upper and lower teeth come together and the relationship of your upper and lower jaw while your teeth are together.
Can TMJ occlusions be asymptomatic?
Dentistry assumes there are “ideal” occluding schemes and jaw relationships, and conversely, there are “mal-occlusions”…but here’s the problem… there has yet to be any research to show that your occlusion determines if you are symptomatic. We’ve all seen someone with a perfect bite and beautiful teeth, yet they are miserable, while someone who is in desperate need of an orthodontist can feel fabulous.
What should a jaw at rest look like?
Essentially, in regards to TMJ, one’s symptoms are far less determined by what one has, but by what one does. When someone has their jaw at normal rest, the teeth are not supposed to be touching. Actually, teeth are very rarely supposed to be touching. Occasionally they will glance off each other during chewing, and for an instant during swallowing.
What does it mean when teeth are in occlusion?
Some people, however, have their teeth “in occlusion” more often than not, that is, their teeth are occluding (or touching). Occluding requires a continuing contraction of certain jaw muscles including those which cover the side of your head-the temporalis
Jaw clenching makes teeth grinding impossible
Jaw clenching can be so intense that “teeth grinding” becomes impossible. As long as the jaw is moving the temporalis is only mildly contracting. At stronger intensities, the jaw will stop moving as the opposing jaws are squeezed together. If the position of the jaw during the clenching event is not “ideal” (it might be shifted over to one side), then one or both jaw joints can be exposed to considerable strain and irritation
Where is jaw clenching strongest?
There is one more piece to this “clenching vs. grinding” puzzle. If the back molars are touching, jaw clenching is strongest. If only the front incisors are touching, jaw clenching is much weaker (30% of its maximum).
What is parafunction?
The purposeless touching of the teeth is called “parafunction”. The intensity, duration, frequency and jaw position during the parafunctional events determines the nature of your symptoms.
So how does parafunction tie in with migraine?
Trigeminal nerve stimuli
Migraine disease is a disorder of the trigeminal nerve system. The sensory component of the trigeminal nerve collects information from all three of its divisions. Information is categorized, with negative or “noxious” input being acted upon depending on its significance. For example, a taco chip that scrapes the roof of your mouth during chewing is not deemed to be worthy of responding to, while nearly the same act performed by a dentist with a similar feeling tool can elicit a protective response.
Trigeminal sensory dysmodulation and migraine
The decision of whether or not to respond to noxious input is called “modulation”. “Dysmodulation” occurs when an otherwise normal input is inappropriately acted upon. A migraine pain event results from “trigeminal sensory dysmodulation”, when normal sensations from certain triggers(particular foods, smells, etc.), cause the trigeminal nerve to secrete chemicals that result in the swelling and burning sensation around the brain, or sinuses, or throughout the mouth and jaw, that is, migraine pain.
What causes trigeminal sensory dysmodulation?
So how does the trigeminal sensory system develop a case of dysmodulation? Most probably, it is being exposed to an excessive amount of noxious input, called “nocioception”, which may be fatiguing the system and keeping it from behaving normally. That’s why when you visit a health care provider regarding your migraines, not only do they want to identify your triggers, they want to find what’s been making you “triggerable”.
Jaw clenching while asleep with migraine
Jaw clenching when you are asleep produces a massive amount of noxious input and the typical jaw-clencher wakes most every day with some degree of headache. In fact, many chronic migraine sufferers don’t mention the “daily background headache” to their doctors in fear of having them labeled as "rebound” headaches.
View Dr. Boyd's YouTube video here: http://youtu.be/9nUpKtUzPo4
Dr. Boyd designed and patented the NTI (nociceptive trigeminal inhibition) device, for the relief of his own chronic tension-type headache and frequent migraine attacks. The NTI specifically limits clenching intensity, and was approved by the FDA for the prevention of medically diagnosed migraine pain as well as migraine associated tension-type headaches.
As the founder of the Headache Prevention Institute in Michigan, Dr. Boyd has extensive experience treating patients suffering from chronic tension-type headache, migraine, and jaw disorders. He is the past Director of Research and Senior Clinical Instructor at the White Memorial Medical Center Craniofacial/TMD Clinic in Los Angeles, and is currently a practicing clinical consultant at the Neurology and Headache Center of Southern California in addition to pursuing medical research opportunities with the NTI.
How much has your migraine disease changed or evolved over time?