Your Jaw – the Temporomandibular Joint
Painful joints frequently frustrate patients — they are unable to do what they want, when they want, or how they want to do so. But in my experience, the most frustrated patients do not have a sore neck, back, shoulder, or knee. No, the most frustrated patients present with a painful jaw. Jaws can be significantly painful and present major barriers to everyday life — but even more significant for many patients is the frustration that comes from having so few options available for treatment!
With that in mind, today we review temporomandibular joint (TMJ) pain, breaking things into a few components:
- What is the TMJ?
- Who is impacted by TMJ pain?
- How did I end up with TMJ pain?
- Why does my TMJ make noises?, and
- Does Manual Therapy (like Chiropractic) help with TMJ problems?
What is the TMJ?
The joint that makes your jaw, called the temporomandibular joint (TMJ), is located immediately in front of the ears. Two bones create this joint: the bone from your chin (the mandible), and a bone from your skull (the temporal bone). This joint is responsible for allowing movements of the jaw, like protrusion (sticking the chin forward), retraction (drawing the chin backwards), lateral deviation (moving the chin side-to-side), and opening or closing. Each of these motions is important for common daily functions like chewing, talking, swallowing, etc.
Although the TMJ looks like it is shaped similarly to the shoulder (a “ball in socket” joint), it is actually more complicated. An articular disc is located between the two bony surfaces of the TMJ, which divides the joint into superior and inferior (top and bottom) parts. As a result, to move properly during mouth opening, the jaw must first rotate during opening (the mandible rotates on the disc — bottom part of the joint), and then glide forward to complete opening (the mandible and disc glide on the temporal bone — upper part of the joint).
To understand this better, follow these steps:
- Place your fingers on the condyle of your mandible (the round “knob” immediately in front of your ears). Keep your fingers here throughout this exercise.
- Now place your tongue on the roof of your mouth, and attempt to gently open you jaw. You should notice that very little changes — this is the mandible rotating on your disc!
- Remove your tongue from the roof of your mouth, and continue opening the jaw. You should notice a large change here — the condyles of your mandible slide forward, together with the disc, as your jaw opens completely!
This is a rather complicated process, but consider if the disc wasn’t present, and we were only able to rotate at the jaw (the first half of the exercise) — we would have a very limited ability to open our mouth wide!
Each step in this process is controlled by our muscles of mastication (chewing muscles): the temporals, masseter, medial pterygoid, and lateral pterygoid (pronounced TARE-uh-goid). The joint is also supported by ligamentous structures, including the joint capsule and temporomandibular ligament, stylomandibular ligament, and sphenomandibular ligament.
Who is impacted by TMJ pain?
According to the National Institute of Dental and Craniofacial Research, the prevalence of temporomandibular joint problems (the number of active cases at any given time) ranges between 5-12% of the population — so this is not an uncommon problem for people. Women appear to suffer from TMJ problems more than men, and younger populations have a greater number of cases than older populations.
How did I end up with TMJ pain?
Usually, these problems are attributed to a mechanical dysfunction (improper muscle action), direct trauma to the TMJ (striking or being struck by something), bruxism (grinding your teeth), or asymmetrical use of the jaw (chewing on one side only). Other factors can lead to jaw pain as well, but typically at least one of these are involved.
Regardless of how it occurred though, your TMJ complaint likely falls into one (or more) of these four categories:
- Muscle Related Pain
- Joint Related Pain
- Degenerative Joint Disease
- Headache related to TMJ Disorder
These categories are broadly established by the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), published by Schiffman et al. (2014) in the Journal of Oral & Facial Pain and Headache. (There are specific subcategories to the DC/TMD, but that moves beyond the scope of this posting — if interested, it is publicly available here)
Why does my TMJ make noises?
Sometimes, when people open their jaw fully, it is accompanied by one or more noises or sounds. Some people experience “clicking”, “popping”, or “grating” (like grinding). So why is that?
As discussed previously, the TMJ is a complicated joint — there are numerous muscles pulling in different directions, a delicate relationship to maintain between the mandible and temporal bones, and a disc which buffers and supports movements at your jaw. Each of these components needs to work as intended, at the right time, and in the correct balance for proper movements to occur.
For example, let’s consider how the jaw should function. We know that rotation occurs first, and then the mandible glides forwards for complete opening of the jaw. This happens because the lateral pterygoid muscle has two attachments: the superior head attaches to the disc itself, and the inferior head attaches to the mandible. When this muscle contracts to begin jaw opening, therefore, the disc slides forward slightly to partially block the mandible from moving forward — meaning the pull of the lower head only creates rotation initially. During the self-test described earlier, this is the phase where your tongue remains on the roof of your mouth.
However, when the forces become greater, both the disc and mandible move forwards together, on to the front aspect of the joint — something called the “anterior eminence”. Here, the disc is acting strictly as a buffer, providing a more stable contact surface for the mandible. Without the disc here, we would be much more prone to jaw dislocations. (See image below).
But so what, right? How does this relate to the noises your jaw makes?
Each of these actions needs to work as designed — otherwise, noises sometimes occur:
- The disc doesn’t reset properly, and sits slightly forward at the beginning of opening? This may cause the mandible to slide over the posterior part of the disc — CLICK!
- You’ve already clicked on opening, and now as you close the mandible shifts backwards out of sync with your disc just as you complete the closing of your jaw — CLICK!
- And if you’re really having an unfortunate time, the disc gets stuck on the anterior eminence, blocking the mandible from even getting to the gliding stage — now you can’t even open your jaw!
Any number of reasons could cause one of these dysfunctions to occur: poor muscle function, irritation of the joint or joint structures, sudden impact to the jaw, changes to the structure of the joint (like arthritis), etc.
But despite having gone through all of the above, let me be very clear about this final point: sometimes joint noises are simply idiopathic, which means their cause is unknown! Noises on their own are common (lots of people have them) and they don’t necessarily indicate a problem or clinical dysfunction of your jaw. So if you notice you have jaw noises, but no pain or limited movement, please do not conclude from this blog posting that you have a TMJ dysfunction — clinically, it might not mean anything at all!
Does manual therapy help with TMJ problems?
What we’ve seen:
- For what it’s worth, we’ve seen a number of TMJ complaints resolve successfully using manual therapy based treatments in our office. This means treating TMJ conditions with a combination of hands-on approaches like muscle massage, stretching, and joint mobilization, and supplementing this approach with other tools like laser therapy and acupuncture. We are thrilled to see consistent results for patients using this approach, but we understand that more objective information is available in the scientific literature too — so here it is.
What the research shows:
- Manual therapies targeting musculoskeletal approaches to TMJ have been found to be effective for dealing with TMJ problems. For example, a recent systematic review and meta-analysis by Martins et al. (2016) reviewing this type of approach to treating TMJ disorders (things like massage or joint mobilization/manipulation) found significant and clinically important improvements in jaw range of motion and reduced painful complaints when compared to other forms of conservative therapy (like stretching, hot/cold application, modality use, etc). This means both the intensity of the patient’s pain and functional limitations were improved with a manual therapy approach to treatment.
- Another systematic review of trials using manual therapy to treat TMJ disorders (from Calixtre et al., 2015) indicates that manual massage to jaw musculature coupled with cervical spine mobilization or manipulation produces favourable patient outcomes too (decreased pain, increased jaw range of motion). Again, this supports the use of manual therapy to the TMJ for reducing pain and improving function, but also hints at the added effect that treatment to surrounding areas, like the neck, can also offer.
And what about the adjunctive treatments we employ?
- Laser therapy has demonstrated success in improving treatment results for TMJ complaints. Chen et al. (2015), for example, recently completed a meta-analysis of 14 high quality studies, concluding that laser therapy can significantly improve functional outcomes of TMJ disorders.
- Acupuncture has also been demonstrated to produce a positive effect for TMJ conditions, though there is more debate about how much and to what degree depending on which studies you review. A meta-analysis submitted by Jung et al. (2011) in the Journal of Dentistry, for example, describes limited evidence for acupuncture effects on TMJ disorders – but the general trend leans towards favourable effects of acupuncture as compared to sham treatment*, particular for reducing muscle tenderness.
- Even the much-maligned ultrasound therapy has shown some evidence of improving TMJ complaints, as a study published by Ucar et al. (2014) demonstrates. They compared groups of patients with TMJ complaints receiving home exercise program alone to a home exercise program in conjunction with ultrasound therapy to the jaw and surrounding muscles, finding that pain relief and mouth opening ability were both greater for the group receiving ultrasound therapy with exercise.
What this means:
Yes. To put things more simply, adding manual therapy targeting the TMJ and surrounding muscles can provide a tangible benefit for jaw complaints. While true that each individual therapy may not solve a TMJ complaint on its own, there is a significant body of research that supports hands-on manual therapy and adjunctive modality use, at least in some regard, for the treatment of TMJ disorders.
- Your jaw has a complicated but specific pattern of movement needed to work properly.
- Alterations to this pattern can lead to noises, pain, and limited jaw function — but it’s also important to remember than some jaw noises are idiopathic.
- A relatively common problem, TMJ disorders appear more often in younger than older individuals, and women more than men.
- Manual therapy, like the treatments provided by chiropractors, continues to develop a growing body of evidence for its effectiveness in treating TMJ disorders.
Dr. Jim Gilliard is a chiropractor in Burlington, ON at Endorphins Health and Wellness Centre— located in the Burlington Professional Centre at 3155 Harvester Road, Suite 406. If you have questions, comments, or wish to book an appointment, please feel free to contact him at your convenience.
- Calixtre LB, Moreira RFC, Franchini GH, Alburquerque-Sendin F, Oliveira AB. Manual therapy for the management of pain and limited range of motion in subjects with signs and symptoms of temporomandibular disorder: A systematic review of randomised controlled trials. J Oral Rehabil. 2015;42(11):847–61.
- Chen J, Huang Z, Ge M, Gao M. Efficacy of low-level laser therapy in the treatment of TMDs: A meta-analysis of 14 randomised controlled trials. J Oral Rehabil. 2015;42(4):291–9.
- Jung A, Shin B-C, Lee MS, Sim H, Ernst E. Acupuncture for treating temporomandibular joint disorders: A systematic review and meta-analysis of randomized, sham-controlled trials. J Dent. Elsevier Ltd; 2011;39(5):341–50.
- Martins WR, Blasczyk JC, de Oliveira MAF, Lagoa Goncalves KF, Bonini-Rocha AC, Dugailly PM, et al. Efficacy of musculoskeletal manual approach in the treatment of temporomandibular joint disorder: A systematic review with meta-analysis. Man Ther. 2016;21:10–7.
- Schiffman E, Ohrbach R, Truelove E, Look J, Anderson G, Goulet J-P, et al. Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) for Clinical and Research Applications: Recommendations of the International RDC/TMD Consortium Network* and Orofacial Pain Special Interest Group†. J Oral Facial Pain Headache [Internet]. 2014;28(1):6–27.
- Ucar M, Sarp Ü, Koca İ, Eroğlu S, Yetisgin A, Tutoglu A, et al. Effectiveness of a Home Exercise Program in Combination with Ultrasound Therapy for Temporomandibular Joint Disorders. J Phys Ther Sci. 2014;26(12):1847–9.