The Temporomandibular Joint

UNDERSTANDING THE TEMPOROMANDIBULAR JOINT (TMJ) AND ITS IMPORTANCE

THE TEMPOROMANDIBULAR JOINT | TMJ

THE HORSE'S MOST CRITICAL AND MOST COMPLICATED JOINT

The horse's temporomandibular joint (TMJ), also known as the jaw joint, is where the horse's lower jaw connects to the upper jaw (skull). You can locate the jaw joints just below the base of the horse's ears, and because of this, pain from the jaw joints is often mistaken for the horse being sensitive around the ears.

Common situations where the horse appears "ear-shy" include when you place earplugs (such as cotton, foam, etc.) in the ears, put on a bridle, trim the ear hair, or even during daily routines like pulling a halter over the ears. If the horse reacts negatively (sometimes quite violently), it may be due to inflammation in the TMJ.

Other common signs pointing to TMJ issues include a crooked bite that quickly returns despite regular dental care, various chewing problems (e.g., difficulty chewing roughage), and tension in the neck and back muscles that only temporarily improve after massage or other treatments (such as acupuncture, laser, light therapy, etc.).


THAT'S WHY THE JOINT IS IMPORTANT

  • Balance and posture
    When the TMJ is working properly, it helps keep the horse in the right balance and posture. If there is pain or stress in the joint, it can affect the horse's posture, which in turn can affect other joints in the body.
  • TMJ Dysfunction (TMD)
    If the TMJ becomes unbalanced or painful, it can lead to TMJ dysfunction (TMD), where the joint structure changes, and other skull bones can become misaligned. This can result in serious health issues such as ulcers, colic, lameness, and reduced performance.
  • Affects performance
    Horses with TMJ problems may experience movement difficulties, stiffness, discomfort with the bridle, and behavioral issues, all of which can seriously impair the horse's performance.


The health of the horse's TMJ is therefore crucial for the horse's comfort, movement, and overall performance.

COMMON TMJ PAIN SYMPTOMS

  • Head shaking

  • Sensitivity around the ears and difficulty with bridling

  • Difficulty opening the mouth fully or yawning

  • Increased sensitivity to sound

  • Shy or withdrawn behavior

  • Jaw misalignment or uneven bite

  • Excessive jaw or tongue activity

  • Stiffness in the neck and/or soreness across the back

  • Crib biting

  • Limited movement of the ears or eyes

  • Head tilt (a more serious sign that may indicate neurological problems)

UNDERSTANDING THE IMPORTANCE

WHAT CAUSES TMJ PAIN?

  • Poorly Fitted Bridles
    An ill-fitting bridle can have an extremely negative impact on the horse. Incorrectly fitted headpieces that cut in and bits that are too tight increase pressure in the neck. If the equipment doesn’t fit properly, it can create imbalance in the horse’s head and neck, leading to stress on the TMJ.

  • Dental Problems
    Untreated dental issues, such as sharp edges or misaligned teeth, can alter the way the horse bites and chews, which in turn affects the TMJ.

  • Injuries and Trauma
    A Blow to the head, falls, or accidents can cause direct injury to the TMJ or the surrounding muscles and ligaments. An example might be horses that are tied up and pull back, unable to break free.

  • Incorrect or Excessive Training
    Overexertion or training that forces the horse to hold its head in unnatural positions can strain the TMJ.

  • Stiffness and Muscle Tension
    Tension in the neck, back, and surrounding muscles can put extra pressure on the TMJ, potentially leading to dysfunction.

  • Improper Chewing Motion
    If a horse chews incorrectly due to dental problems, improper feed, or imbalance in the jaw muscles, it can lead to long-term issues with the TMJ.


These factors, either individually or combined, can affect the horse’s temporomandibular joint, leading to pain, stiffness, and other complications that affect the horse’s overall health and performance.

TRY IT YOURSELF

RELEASE TENSION IN NECK & JAW MUSCLES

Learn how to release your horse’s trigger points at home with Nicoline Braunerhjelm, a professional physiotherapist.

She guides you through three simple techniques to relax the neck and jaw muscles, improving comfort and mobility. Watch for signs of relaxation such as chewing and a lowered head!

* Information Vet. Per Spångfors