What is Temporo-Mandibular Joint Dysfunction?

Ryan Walsworth RMT TMJD

Temporomandibular Joint Dysfunction (TMJD) is classified as a disorder relating to the muscles of mastication and their effect on the jaw as well as their associated structures.

Muscles affected by TMJ Dysfunction
Image Credit: Netters Atlas of Human Anatomy 7th Edition 2019 plate 56

Common TMJ Dysfunction Synonyms

  • TMJD
  • TMJ Pain & Dysfunction Syndrome
  • TMJ Syndrome
  • TMJ Disorder (General disorder associated with opening/closing of the jaw or posture)
  • TMJ Myalgia/ Fibromyalgia (Pain within the muscles of mastication)
  • TMJ Althralgia (Pain within the joint capsule)
  • TMJ Capsulitis/ Synovitis (Inflammation of the joint capsule)

Anatomy and Function of the TMJ

There are 2 temporomandibular joints that enable the mandible to open and close. This motion occurs in 2 components; a rotational component that occurs in the inferior portion of the synovial joint capsule, as well as a gliding component that occurs superior to the articular disc of the joint. The inter-articular disc that separates the superior and inferior portions of the joint capsule is made up of fibrocartilage which lacks innervation and blood supply itself but is attached posteriorly to a highly innervated and vascularized retro-discal tissue which provides both sensory and motor (aka proprioceptive) information to the brain.

TMJ Dysfunction Medial and Lateral Pterygoid Muscles
Image Credit: Rattray’s Clinical Massage Therapy P603

There are several muscles (the muscles of mastication) that play a role in TMJD. These muscles are the medial and lateral pterygoid muscles respectively, as well as the masseter and temporalis muscles. The medial pterygoids, masseters, and temporalis muscles work synergistically to close the mouth with activities like chewing, talking, or yawning, while gravity, as well as the lateral pterygoid muscles, apply opening forces. For most patients, dysfunction at the TMJ becomes evident when there is either pain or a clicking sensation when opening the mouth, or as the jaw sometimes becomes locked in the open position which is sometimes referred to as “lock-jaw”. Under stress, the lateral pterygoid muscles tend to pull forward on the articular disc which causes pain due to its posterior attachment to the retro-discal tissue. In either case, any abnormal sensation or deviation of the mandible on opening is generally caused by several contributing factors:

  • Overuse Injury: Anterior displace of the articular disc due to ligamentous laxity at the TMJ.
  • Joint Pathology: Hypermobility, capsulitis, synovitis, as well as osteoarthritis, and rheumatoid arthritis, can contribute to joint pain when the joint tissue called the synovium becomes inflamed.
  • Muscular Imbalances: Anterior displacement of the articular disc due to muscular engagement by the lateral pterygoid muscles.
  • Pain: Retrodiscal pain associated with the disc being pulled or getting stuck during the opening or closing of the jaw.
  • Postural Dysfunction: Poor postural habits such as head-forward posture, or stress-related postures that affect the supra and infra-hyoid muscles located on the anterior neck.
  • Stress-Related Factors: Clenching teeth or grinding of the teeth (bruxism) can play a role in muscular tension in this area.
  • Breathing Problems: Health issues associated with breathing such as asthma or even irregular mouth breathing habits.
  • Muscular Instability: Weak core muscles of stability around the abdomen and gluteal regions which cause an anterior or posterior shift within the body’s normal center of gravity.
  • Motor Vehicle Accidents or Blunt Force Trauma: Trauma associated with the jaw, cervical spine, shoulders, etc, or anywhere else along the kinetic chain which may force the body to compensate for misaligned joints or muscular weakness.
TMJ Dysfunction Anatomy of the Temporomandibular Joint
Image Credit: Rattray’s Clinical Massage Therapy p600

Common Signs and Symptoms of TMJ Dysfunction

  • Early Stages:
    • TMJ sounds (clicking, popping) occur with jaw movements.
    • Joint pain is associated with clenching or chewing, pain is often worse in the morning with tenderness being noted within the muscles of mastication as well as inside the joint capsule.
    • Headaches within the frontal or temporal regions of the skull.
    • Spasms occur within the muscles of mastication.
    • Increased muscle tone or trigger points within the muscles of mastication, cervical region, or shoulder complex.
    • Changes with a range of motion at the TMJ, including irregular opening or closing, as well as catching or locking in certain positions.
    • Changes in hearing include stuffiness, blockage, or hearing loss that results from trigger points and increased tone within the medial pterygoid muscles.
    • Inflammation is associated with direct or indirect trauma causing capsulitis and pain within the joint.
    • Tinnitus (ringing in the ears), nausea, lacrimation (watery eyes), tooth sensitivity, and even paresthesia or numbness in the area.
  • Later Stages:
    • If symptoms are not corrected the muscles of mastication may develop contractures that limit the jaw’s ability to open and close.
    • Degeneration of the articular disc may exacerbate symptoms further down the road.

Using Massage as an Effective Treatment Tool for TMJD

  • Reduce Inflammation and Edema: In the early phases of treatment, one of the goals may be to decrease the presence of swelling associated with inflammation. Manual lymphatic drainage (MLD) can be used in this case to help manage symptoms associated with edematous tissue.
  • Reduce Myofascial Restrictions: Fascial glides can be used to assess the muscle groups surrounding the joint capsule of the TMJ, and treat any restrictions in the face, neck, and pectoral areas.
  • Reduce Soft Tissue Tension: Passive stretches, as well as compression, and traditional Swedish massage can be used to reduce tension within the muscles of mastication. Intra-oral work is performed by following the patient’s teeth towards the back of the mouth, and compression is applied to both the medial and lateral pterygoid muscles in an attempt to soften the tissue. Treatment within the mouth can sometimes last anywhere from 5 to 10 minutes, and therefore it is very important to discuss the treatment protocol in advance with your patient so that they understand that there may be some discomfort associated with treatment. Please ensure that as a therapist you allow sufficient time for your patient to rest every few minutes.
  • Mobilize Hypomobile Joints: Joint play is indicated in the presence of hypomobility within the cervical spine and shoulder girdles. If the assessment determines a possible subluxation at the TMJ, be sure to refer your patient to a chiropractor for treatment.
  • Reduce Trigger Points or Muscle Spasms if Present: Assess the patient’s musculature around the TMJ in order to determine if this is the cause of the dysfunction. Trigger points may be palpable along with the muscles of mastication, the anterior cervical spine, as well as the pectoral and shoulder girdles. Be sure to check in with your patient regarding any potential referral patterns which may indicate which muscles are affected by the presence of trigger points.
  • Reduce Adhesions in Affected Musculature: Muscle stripping and separation may be used to ensure that all muscle groups are gliding against one another effectively.
  • Restore Range of Motion: Muscle energy techniques can be used to help decrease spasms and restore lost range of motion at the TMJ.
  • Treat Contributing Factors: Assessment and treatment of contributing factors such as poor posture can also affect positive rehabilitation of the temporomandibular joint. Be sure to conduct a thorough intake and postural scan.

For more information on the anatomy and treatment of temporomandibular disorders please watch this short video prepared by osmosis.org

TMJ Dysfunction muscles of mastication
Image Credit: Rattray’s Clinical Massage Therapy P602

Content created by Ryan Walsworth RMT, for more info about the author, click here.

Information Source: Rattray Clinical Massage Therapy: Temporomandibular Joint Dysfunction p546

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