Temporomandibular Joint (TMJ)

Posted on the 16 January 2023 by Fereshteh Yasoubi @physio2health

The temporomandibular joint (TMJ) is formed by the mandibular condyle, the articular eminence, and the fossa of the temporal bone. The articular disc is located between them. The TMJ function enables the movement of the jaw for actions like eating, yawning, and speaking. The temporomandibular joint – the TMJ – is the joint between the skull’s lower jawbone, the mandible, and the temporal bone. The TMJ is responsible for jaw movement and enables chewing, talking and yawning. Temporomandibular disorders, or TMD, refer to pain in the jaw area and limited mandible movement. TMD may be caused by problems in the joint or the muscles surrounding it. Problems in the joint include arthritis, inflammation and internal derangements. When the problem is in the muscles, the condition is called myofascial pain syndrome.

What Are Temporomandibular Joint Dysfunctions?

Temporomandibular joint dysfunctions limit the movement of the jaw. They can cause limitations of the mouth opening, headache, pain in the neck, ear and jaw and clicking sounds when opening or closing the mouth.
A bad occlusion or a way in which we bite, facial asymmetries, bruxism or cervical alterations are some of the causes that in turn can cause muscle problems.

What Is The Cause of Myofascial Pain Syndrome?

Temporomandibular Joint (TMJ) overload is one of the most common causes of muscle problems, producing myofascial pain syndrome. It is characterized by a muscle point that is more tense than normal, which once contacted it’s unable to relax, is painful on palpation and located on a taut band called the trigger point. Each triggers pain that radiates to a specific body part and can cause movement limitation. The most related muscles in the TMJ are the masseter, pterygoid and temporalis. muscle injury muscles cause trigger points can be injured suddenly in accidents, or damage can occur slowly due to repeated movements or poor posture a muscle is composed of tiny fibres which contract and relax in response to messages from the brain when muscle fibres become injured or overstimulated they cannot relax and form contraction knots a trigger point consists of many contraction knots where individual muscle fibres contract and cannot relax fibres extending from the trigger point to the muscle attachments shorten and form a tight band the persistent contraction of muscle fibres compresses blood vessels and decreases their blood supply leading to oxygen starvation and the accumulation of waste products this irritates nerves and causes pain activated pain receptors generate specific referred pain patterns depending on nerve passage and muscle anatomy.

Temporal Muscle Pain

Referred masseter pain can be located in the jaw, teeth, eyebrows, ear, and TMJ. Temporal muscle pain is associated with upper tooth pain and headache. Referred pain from the medial pterygoid muscle radiates to the Temporomandibular Joint (TMJ) region near the ear, mouth, and upper neck and can create difficulty swallowing. Myofascial pain syndrome is very common and can occur in patients with a normal temporomandibular joint. The syndrome is characterized by the presence of hyperirritable spots located in skeletal muscles called trigger points. A trigger point can be felt as a nodule of muscle with harder-than-normal consistency. Palpation of trigger points may elicit pain in a different location. This is called referred pain. Trigger points are developed as a result of muscle overuse. Commonly, chewing or mastication muscles are overworked when patients excessively clench or unconsciously grind their teeth during sleep. The medical term for this condition is “nocturnal bruxism.” A trigger point comprises many contraction knots where individual muscle fibres contract and cannot relax. The sustained contraction of muscle sarcomeres compresses the local blood supply, resulting in an energy shortage in the area. This metabolic crisis activates pain receptors, generating a regional pain pattern that follows a specific nerve passage. The pain patterns are therefore consistent and are well documented for various muscles. Trigger points in the masseter refer to pain to the cheeks, lower jaw, upper and lower molar teeth, eyebrow, inside the ear and around the TMJ area.

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What Are Some Other Muscle Problems?

Lateral pterygoid muscle pain is usually felt next to the ear and in the upper jaw. These muscle problems can spread to other body parts such as the neck, shoulders, back, arms and legs. 

What Is The Treatment for Myofascial Pain Syndrome?

The treatment of Myofascial Pain Syndrome consists of releasing the trigger points and restoring muscle length and strength. Treatments may include manual therapy, thermotherapy, infiltration with anesthetics or medication in the affected area, dry needling and stretching. 

Trigger points in the medial pterygoid refer to pain in the Temporomandibular Joint (TMJ) region in front of the ear, inside the mouth and upper outside of the neck. They may also manifest as sore throat and difficulty swallowing. Pain from lateral pterygoid trigger points can be felt in front of the ear and on the upper jaw. Treatments aim to address bruxism, relieve muscle spasms and release trigger points. Treatment options include:

– Therapies: stress management, behavior therapy, biofeedback – to encourage relaxation.

– Dental night guards: Splints and mouth guards – to protect the teeth from damage.

– Medication: pain relievers, muscle relaxants, botox injections.

– Trigger points release techniques such as needling and “spray and stretch.”

What Is the Myofascial Pain Syndrome?

To understand myofascial pain syndrome and what trigger points are, it’s helpful to know the basic anatomy of the spine and complex groups of supportive muscles in your back. Hold your body upright and allow your trunk to twist move and bend in many directions each muscle is surrounded with a connective tissue sheath called fascia it stabilizes and separates muscles reducing friction between them; myofascial pain syndrome is characterized by ongoing muscle pain and tenderness, it can affect various muscles and fascia of the body. Your points develop in myofascial pain syndrome which are small areas of tight painful muscle tissue, their size varies from a peanut to a pea sometimes trigger points can be felt under the skin pressing on the trigger point, it is painful, but pain may occur not only on the spot but also in a different part of the body this is called referred pain this might make the diagnosis of myofascial pain difficult fortunately typical patterns of referred pain are well known and documented for many trigger points.

What Are the Symptoms of Myofascial Pain?

Trigger points of myofascial pain syndrome often can be found in the head, jaw, neck, shoulders, upper back, lower back and extremities both sides of the body are often affected myofascial pain symptoms include persistent pain in localized muscles that is usually deep and aching affected muscles often become tight and weak with a limited range of motion, and small painful knots may be felt under the skin but not always; sometimes trigger points lie deep inside the muscle pain from a trigger point is often felt in a remote region of the body this is called referred pain typical patterns of referred pain are well known and documented for many trigger points.