TMJ (temporomandibular joint dysfunction) is something I see and treat commonly in clinic. Pain around the jaw and face, difficulty with opening or closing of the mouth and head and neck pain are just some of the common symptoms associated with the condition. Clients will often ask how they managed to find themselves suffering from the condition in the first place.
This can be a tricky one to explain as there could be a number of potential causes including poor bite alignment, chronic clenching or grinding of the teeth (bruxism), an accident or trauma e.g. whiplash, chronic illness, such as lupus, fibromyalgia, chronic fatigue syndrome, or extensive dental work.
In this blog, I would like to concentrate on another potential cause which is often overlooked – muscle imbalances caused by poor posture!
When I explain to clients that tight muscles may be a major contributor to their TMJ pain they often struggle to see the link between the two. It’s understandable that to anybody who has no previous knowledge or training in the subject, having someone tell them their ongoing jaw pain may be due to them not standing or sitting up straight can seem a little confusing.
With this in mind, I’ve decided to write a blog which will (hopefully!) help to shed some light on the posture/muscle/ TMJ relationship….wish me luck!
Firstly, a little bit of anatomy to help us get started….I’ve included some pictures to help us along!
What is the Temporomandibular joint?
The joint is made up of the articulating bones, the articular disc and the muscles which surround and attach to the joint. I’ve given a brief description of each below…
The temporomandibular (tem-puh-roe-man-DIB-u-lur) joint is the joint between condylar head of the mandible (jaw bone) and the temporal bone.
The TM joint acts like a sliding hinge, connecting your jawbone to your skull. You have one joint on each side of your jaw.
Within the joint lies the TMJ articular disc, which is made up of cartilage and acts to divide and cushion the mandible and temporal bones. The TMJ articular disc enables the joint to glide freely as we open and close our mouths.
Often, TMJ sufferers will present with a disc which has shifted forward within the joint (also known as becoming anteriorly displaced). When this happens, the joint will not be able to glide smoothly as the jaw opens and closes. This uneven movement will result in the client experiencing the audible popping and clicking often associated with TMJ.
You can see in the image on the right an example of the TMJ disk being displaced forwards as the mouth is open. This can cause the clicking and popping sensation often associated with TMJ.
There are four muscles which make contact with the TMJ : the masseter, temporalis, and two pterygoids muscles. The main movements the muscles produce are closing of the mouth and bringing the jaw forwards. The muscles are primarily used when we are chewing and eating;
As you can see the muscles of the TMJ can have a strong influence on the position of the jaw. Potentially, these muscles can move the jaw more over to one side then the other (for example, if the muscles are tight on the left side of the jaw then the jaw can be pulled more to the left side. This is more noticeable if we observe ourselves in the mirror as we open and close our mouths). These are also the main muscle we use to close the mouth.
As you can imagine, if any of these muscles become overworked, tight or short then they can potentially have a big impact on the positioning of the jaw…but how do these jaw muscles become tight in the first place?
Muscle Imbalances Potentially Causing TMJ?
The muscles of the jaw can become restricted for a variety of reasons as we have already discussed but for this discussion we will concentrate on how posture can affect the jaw. There are several different postural distortions which could be contributing to TMJ but for today, lets look at one of the major culprits – forward head posture.
Clients presenting with TMJ will often report a tightness to the muscles of the neck and upper shoulders. A major cause of this muscle tightness is due to the head being held in a forward position for an extended period of time; a postural dysfunction commonly termed as forward head posture.
Clients presenting with a forward head posture will often be spending long hours during the day sat at a desk in front of a PC.
Typical example of forward head posture adding extra strain to the neck and eventually, jaw muscles!
Clients with forward head postures are often vulnerable to increased pressure to the muscles at the back of the neck and shoulders. This is due to the neck and shoulder muscles becoming overworked as they attempt to take the load of the increased weight of the head as it is held in the forward held position. The body will often attempt to reduce the pressure on the neck and shoulders by recruiting other muscles to help pull the head backwards in a more neutral position over the shoulders. Often in this case, the muscles at the front of the neck (around the throat and under the chin – commonly an area of tenderness for TMJ sufferers) known as the Supra Hyoids, will be recruited. One of the roles this group of muscles has is to pull the jaw backwards but in this instance the body is using the Suprahyoids to not only pull the jaw back but also to try and pull the whole head backwards in an attempt to reduce the strain on the neck and shoulders.
As you can see the hyoid muscles are generally used to open the mouth and retract the jaw. Further compensations can occur as the body recruits other muscles in an attempt to close the jaw.
The problem with this is, the hyoid muscles are also jaw openers, which means as these muscles work harder to to pull the jaw (and head) backwards, they will also begin to hold the mouth in an open position. As the body is not comfortable with the mouth being held in a permanently opened position, the powerful jaw closure muscles will then be recruited in an attempt to close the jaw.
As we discussed at the beginning of this blog the muscles which close the jaw are the masseters, temporalis and pterygoids – which happen to have an attachment to the TMJ and the articular disc!
As these muscles continually work in an attempt to keep the mouth closed they can become overworked, short and tight which can result in a pull being exerted on their attachment with the TMJ disc. This pull can lead to the disc being displacement anteriorly (remember the jaw clicking and popping we discussed earlier?) which will usually result in the jaw pain often associated with the condition.
The client will often find themselves in a constant pain/ spasm cycle.
There can be a variety of causes of TMJ as mentioned at the beginning of this blog, but muscle imbalances, often caused by poor posture, should be investigated in all cases.
I often find the key to providing long-term relief to TMJ sufferers is to not simply treat the muscles around the jaw and neck but to also address any postural issues (such as forward head posture) which can be creating tension throughout the upper body and, potentially, the jaw.
I hope this blog has given some useful insights into what can potentially be a major contributor of TMJ pain. It’s a tricky topic to explain but I hope some of what we have discussed will at least give TMJ sufferers a little more insight into what can potentially be the root cause of the condition.
Body in Balance Therapies are a Sports and Soft Tissue Therapy clinic based in West Kirby on The Wirral, specialising the treatment of TMJ. Please contact us if you have any questions or would like to find out more.