Temporomandibular Joint: Disorders and treatment

Javier Colomer 7 min. of reading Injuries Leave a comment

Temporomandibular disorders (TMD) mainly affect people between 20 and 40 years old, with an average age of 34. Overall, around 75% of adults may experience at least one abnormal symptom linked to temporomandibular joint (TMJ) disorders (the usual acronym for this group of conditions).

Main causes of TMD

The set of muscles, teeth, bones, and joints that make up the jaw allow movements in all three planes of space, besides being used for talking, chewing, and swallowing.

It seems one of the main causes is the peak in disc displacement around the third decade of life, and for inflammatory and degenerative joint disorders around 50 years old.

However, it can’t be said there’s a single cause linked to TMD, but rather they should be understood as a group of related disorders with common features.

Symptoms

Probably the most common symptom is crepitus, indicative of osteoarthritis. It’s a sustained sound, often described as a gritty noise during mouth opening and/or closing.

It can be distinguished from clicking, which is a brief noise occurring at a specific moment, usually caused by a condyle-meniscal dislocation with anterior disc displacement (after which the gritty sensation mentioned earlier may appear).

There doesn’t have to be pain in the jaw when opening or closing, in which case TMD is linked to joint hypermobility. On the other hand, subluxation and dislocation of the TMJ can cause pain or functional impairment:

Subluxation = clicking during opening and closing. The condyle shifts, but contact between the two joint surfaces remains. When there’s pain, it often radiates to the ear, same side of the head, or face.
Dislocation: When it happens, it causes intense pain, limited ROM, and no joint clicking during opening or closing, but functionality decreases over time due to complete separation of joint surfaces. It needs to be put back (reduction) by a doctor.

Treatment

Since the etiology of TMD isn’t fully clear and can even be due to referred pain from other body areas, a wide range of multidisciplinary therapeutic solutions has been proposed.

Among them:

Psychosocial and behavioral interventions

Stress at work and daily life has been proposed as one of the main causes of this disorder, along with other psychosocial factors, including fatigue linked to overtraining.

Cognitive-behavioral therapy has been used as a psychosocial intervention, showing effectiveness in some meta-analyses. Along the same lines, individual or group relaxation techniques (yoga, listening to relaxing music/sounds, deep breathing…) and even hypnosis can help reduce symptoms.

Regarding hypnosis, there’s some controversy since it can’t be classified as a “scientifically proven method,” but as we’ll see later, it’s on a similar level to occlusal splint therapy, which is more commonly prescribed as treatment.

Of course, if the cause is overtraining, the solution is well known: strategic detraining.

Physiotherapy, osteopathy, and other manipulative techniques

There are many different approaches in physiotherapy, but exercises aimed at increasing jaw movement range are commonly involved, and although it’s always advisable to be guided and treated by a professional, a large part of this physical therapy can be done at home.

The simplest method is regular stretching within pain tolerance, using thumb and index finger in a scissor-like maneuver. With habit, the possible pain-free ROM will gradually increase.

Massage therapy using friction applies surface pressure causing transient ischemia, followed by reactive hyperemia. This would inactivate trigger points and disrupt small fibrous adhesions that may have formed in the muscle.

Trigger points in the main muscles involved in jaw movement can cause someone with TMD to feel sore throat, ear ringing, or a blocked sensation; and can result from overuse due to:

Poor posture: pronounced kyphosis, forward head, shortened pectoral muscles
Bruxism, biting the tongue, or the need to chew gum constantly.

Sometimes, physiotherapy includes the use of transcutaneous electrical nerve stimulation (TENS), which can block pain by stimulating superficial nerve fibers and lead to acute pain reduction, possibly due to endorphin release. However, I think it’s important to warn those who have it at home and are thinking of using it that it shouldn’t be seen as a standalone method, but complementary to physical therapy. Of course, always better under professional supervision.

To wrap up this section, there’s a treatment whose evidence lags behind physiotherapy but could improve symptoms linked to TMD.

We’re talking about osteopathic manipulative treatment (OMT), which uses precise forces applied by the doctor to improve muscle and ligament function and optimize blood flow to an area. It’s mentioned last among physical therapies because, according to the literature, that’s its current ranking.

Occlusal adjustment devices

mouthguards, unloading devices or splints, and occlusal adjustment pieces have been used to treat teeth grinding and clenching, as well as TMJ disorders. It’s believed these aids redistribute forces evenly across dental arches and/or achieve a more favorable condyle position in the fossa, aiming to reduce tooth wear, bruxism, and TMD.

Well, that’s what’s believed and what those who prescribe them as treatment rely on. However, it’s worth noting this topic is controversial since, according to the latest meta-analyses (see sources), they’re not linked to significant improvement compared to passive methods, and many cases report worse subjective pain sensation when used.

Other factors

Lack of sleep, poor dietary habits, nutritional deficiencies, or eating hard foods also affect the jaw and its disorders.

Conclusions

Knowing the symptoms and signs of TMD is vital for correct diagnosis and to steer treatment in the right direction without confusing it with more common conditions like neck pain.

Physiotherapy, mainly with active methods to increase ROM and manage trigger points, is the most effective method alongside global relaxation techniques. All this can be a consequence (and cause) of biomechanical alterations in the overall posture of our body.