When people have pain opening and closing their jaw, the phrase TMJ muscles may not immediately come to mind. After all, when you have pain in your jaw you might think it’s from a tooth, from the jaw, or from the TMJ joint itself.
Yet the muscles involved in TMJ function are often one of the most defining causes of TMJ pain.
In this article, we will discuss the muscles of TMJ disorder, why you feel muscle pain, and how to relax jaw muscles during a bout of TMJ pain.
TMJ Disorder, Muscles, and Pain
There are numerous muscles of the head and neck that can cause pain. But they all have one common similarity: a muscle wants to be used the way it’s intended to be.
What is happening when a muscle exhibits pain is that the muscle was strained in a way which it is not intended to be.
Consider a weightlifter at a gym. With proper form and weight selection, the muscles might have some minor tenderness after a workout, but for the most part, muscles do not feel excessive pain the following day.
But for a moment think about a weightlifter who taxes the muscles with an excessive amount of weight, in poor form, and for an excessive duration. What happens the following day?
It’s a different story. The muscles feel painful, sore to touch, and have decreased range of movement. That’s the presentation of muscle injury.
The same happens to the muscles of the head and neck, the muscles feel pain when they are strained in an excessive manner. It’s similar to a weightlifter except it’s also different. Allow me to explain.
What I want you to realize is that it’s not that you’re intending to strain your jaw with weight. It’s that the mechanics are not in harmony.
The best way to think of it is that your jaw is not functioning with proper form, even when no weight is applied at all. If there is even a slight misalignment between the top and bottom jaw, it places more strain on some muscles more than others…sometimes severely so even when not chewing. And when that happens every day for a long enough period, that slight lack of harmony in jaw function creates some pretty serious muscle soreness and pain.
Primary Muscles that Cause Temporomandibular Joint Disorder
There are four primary muscles that are responsible for the function of the lower jaw. When the jaw isn’t functioning in ideal harmony, these are generally the muscles which will begin feeling soreness first.
We will discuss each of the four muscles in detail below, but here’s what I want you to take away. Each of the muscles is designed for a specific movement of the jaw. It wants to work in a controlled manner.
During TMJ disorder, there are issues which may disrupt the muscle. Each of these muscles might be overloaded, worked in excessive duration, or may be strained trying to compensate for the movement of another muscle which is overworked.
The takeaway is that each of these muscles are designed to work in synergy with the others. Pain is caused by the lack of harmony by any number of causes.
And without further ado, here we go with the details of each TMJ muscle below:
The masseter muscle is positioned on the outer sides of the lower jaw, the mandible. It is a strong rectangular muscle, which some texts have reported as the strongest muscle in the body pound for pound. The muscle originates from the zygomatic arch and extends down to the mandibular angle. The masseter is responsible for the elevation and also the protrusion of the mandible.
The temporalis muscle is a fan shaped muscle positioned to cover the majority of the sides of the head in the area of the temples.
The anterior portion of the temporalis is responsible for elevating the mandible and the posterior part of the temporalis is responsible for pulling the mandible posteriorly which is known as retrusion.
Lateral pterygoid muscle
The lateral pterygoid muscles are small fan shaped muscles tucked in the infratemporal fossa which can be felt by palpating in the mouth just above the maxillary second molar area.
The lateral pterygoid is an aid in the movements of protruding and depressing the mandible when contracting bilaterally and by guiding the rotation of the mandible unilaterally.
Medial pterygoid muscle
The medial pterygoid is a muscle that connects on the inner surface of the mandible and acts as a sling with the masseter muscle on the outer surface.
The medial pterygoid is responsible for two movements. When only one side contracts the medial pterygoid assists with the rotation of the mandible, and when a person contracts both sides, the medial pterygoid elevates and protrudes it.
Secondary TMJ Muscles that are Painful
Although there are four muscles which are intended to move the mandible, in a case of TMJ disorder, all bets may be off. The lack of harmony and the uneven load of force can cause pain in other muscles.
Compensation of Muscles
In times when the primary muscles of jaw function are fatigued, other muscles of the head and neck begin to try to compensate in a subconscious manner.
Think of it as if you sprained your ankle. What happens? You probably would put more weight on the other leg to subconsciously compensate. It is a protective compromise and the same happens with the head and neck.
So what happens is as the primary muscles of the jaw fatigue, the other muscles of the head and neck begin to bare additional stress in a compensatory manner. That is why patients can have pain in the areas of the forehead (the glabellar), the back of the head (the occipitalis), the sides of the neck (the sternocleidomastoid), and the shoulders (the trapezius).
Of course these pains are not always related to TMJ disorder. Someone may coincidentally have a shoulder issue which is separate from the TMJ pain, however, there is a possibility the two areas of pain could be linked and exacerbating each other.
Uneven Load of Muscles
Another reason people may have pain in muscle areas which are seemingly unrelated to the jaw is due to the uneven levels of force which are common with TMJ disorder.
If one part of the jaw is closing with more force than another, the structures surrounding those areas may begin to absorb more pressure than they should.
That is why some people may develop pain in various parts of the head and neck such as in the area of the ears and pain in what feels like behind the eyes. Again, it’s important to realize these types of pains are not always linked, but many times they can be.
How to Relax Jaw Muscles and TMJ Pain
The muscles of the jaw are complex because there are several muscles which are working together to create a symphony of movements. But it all comes down to basic principles. The muscles seek to function in proper form, with a reasonable amount of force, and for a limited duration.
What happens in many patients with TMJ disorder is that the top and bottom jaw are not aligned as well as they could be. It might be as seemingly insignificant as one tooth hitting harder than the rest when a patient bites together. That small deviation can cause the jaws to function in poor form.
You can also imagine how a tooth hitting slightly too hard could also trigger changes in our habits. For example, it’s common for a patient with TMJ disorder to clench and grind during the day or night. It’s a reflex by which the body is expressing that the jaw feels out of harmony. And that’s not good because it restricts the muscles from resting if the teeth and clenching and grinding instead of resting.
And it doesn’t stop there. A misalignment between the top and bottom jaw can even create an excessive amount of force in the muscles. All these factors can be the source of pain.
So by now you get it, and you’re wondering how to correct the pain.
To relax the jaw muscles and reduce TMJ pain, it comes down to the position. Is the position that the patient is functioning in causing pain?
And to evaluate that, the simplest and most effective way it to create an appliance to test different jaw positions. If the patient’s symptoms improve when wearing the appliance and worsen without it, that’s feedback. It provides valuable information of how the position is straining the muscles.
It’s important to note that there are also adjunctive treatments which further support finding the right jaw position and reducing muscle pain. Some of the common treatments that help reduce TMJ muscle pain are botox, acupuncture, muscle relaxers, physical therapy, and chiropractic.
TMJ Muscles: The Bottom Line
The bottom line is that the pain from TMJ disorder is often caused by muscle pain. Its not the only cause but it’s a common offender.
The muscles are not usually the cause of the pain by themselves, there is usually a deviation in the jaw position which is causing an excessive force on the muscles, poor form, or lack of ability for the muscles to rest.