What is Temporomandibular Joint Dysfunction Syndrome?

Temporomandibular Joint Dysfunction Syndrome (TMJD from herein), is a broad term that refers to the dysfunction of the articulation between the mandible and the cranium – aka the TMJ or temporomandibular joint. TMJD is not exclusively a disorder of the bony structures, but may also be a result of hypertonic muscles which affect the joint and therefore cause symptoms.

Temporo refers to the temporal bone of the cranium (skull), and mandibular refers to the mandible or jaw.

Symptoms of Temporomandibular Joint Dysfunction

In early stages there is often a clicking or popping noise when a client opens or shuts his or her mouth. As the condition progresses, there may be pain at the site, which is just in front of external auditory meatus (ear canal), the temple or the teeth. The noise or the discomfort usually presents unilaterally, however it can present bilaterally.

Poor coordination of the muscles leads to deviations in movement as the jaw opens or closes. For example, if looking in the mirror, a client may notice that when she opens her mouth, her jaw is pulled to one side.

In severe cases, the jaw may become dislocated and stuck open, and the surrounding muscles may spasm.

Who is at risk for TMJD ?

Temporomandibular Joint Dysfunction appears to occur more often in women, and in the age group of 20 – 40 years. It is common in people who have suffered trauma to the jaw and face, who have suffered whiplash (a WAD injury) or who may have had a lot of dental work or surgery. Other conditions such as excess muscle tension can lead to malocclusion, or arthritis may affect the joint.

TMJD also appears to worsen in those who have extreme postural deviations, such as scoliosis or anterior head carriage.

Anatomy of the Temporomandibular Joint

The TMJ is a hinged synovial joint, and is an articulation of the head of the mandible with the mandibular fossa and articular tubercle of the temporal bone.

Within the joint is an articular disc whose purpose is to cushion the bony surfaces during movement. This articular disc divides the joint capsule into a superior and an inferior compartment: superiorly between the disc and the mandibular fossa, and inferiorly between the disc and the head of the mandible.

The TMJ is located anterior to the external auditory meatus or ear canal, hence the ear pain in some cases of TMJD.

The mandible is suspended from the cranium primarily by the fibrous capsule of the TMJ and lateral ligament of the joint, in addition to the sphenomandibular and stylomandibular ligaments medially and inferiorly. The latter 2 ligaments serve to stabilize the joint during movement by opposing the pull of the capsule and lateral ligament.

Movement of the Temporomandibular Joint

The temporomandibular joint is moved by what are known as “the muscles of mastication”. There are 4 of these muscles, the temporalis, masseter, lateral and medial pterygoids.

The primary mover of the TMJ during opening (or depression) of the jaw is actually gravity – this is assisted by the lateral pterygoid muscle as well as the supra- and infrahyoid muscles. The lateral pterygoid is the only muscle of mastication that depresses the jaw.

The lateral pterygoid, and to a lesser degree, the masseter and medial pterygoids act to protrude the chin.

To elevate the mandible (close the mouth) the temporalis, masseter and medial pterygoid muscles contract.

To retract the chin, the temporalis and masseter contract.

Action of the disc during an opening/depressing movement of the TMJ

There are 2 movements which occur in the TMJ – first, the head of the mandible rotates anteriorly, secondly, the head of the mandible glides anteriorly as it continues to rotate anteriorly.

To open the mouth, the lateral pterygoids contract, and with the assistance of gravity, pulls the articular disc taut in the joint capsule.

As the head of the mandible moves anteriorly along the mandibular fossa of the temporal bone, the articular disc is pulled anteriorly as well, always staying between the two articulating bones. The correct end-range of this movement is at the articular tubercle of the temporal bone.

Dislocation of the TMJ occurs when the head of the mandible slips anteriorly to the articular tubercle. This may occur due to spasm of the lateral pterygoid muscle as the client opens their mouth.

Dislocation may also occur due to a sideways blow to the jaw when the mouth is open. It is not uncommon for the arm of the mandible to break instead of the actual TMJ dislocating.

Functional dislocation of the articular disc occurs when the disc is unable to move normally with movement of the head of the mandible. This dislocation may occur anteriorly or posteriorly to the head of the mandible.

An anterior dislocation can be differentiated by difficulty and pain with opening of the mouth, with the available movement being very limited. This is a result of the disc becoming compressed between the mandibular head and the articular tubercle and lateral pterygoid.

Difficulty and pain with elevation (closing) of the mandible, and a possible inability to close the mouth completely, is an indication of a posterior dislocation, where the articular disc is jammed against the posterior aspect of the joint cavity.

Failure of the disc to move properly within the joint capsule is believed to be the cause of the clicking sound which is often heard. The incorrect movement may be due to hypertonicity of the muscles of mastication, articular surface degeneration etc.

© Copyright 2010 Jodi Forsythe
www.whymassagetherapy.com
All Rights Reserved.

What is the study of Anatomy?

The study of anatomy refers to the study of the structures of the body.

There are various types of anatomy with which a massage therapist must be familiar. These are:

Clinically oriented anatomy
emphasizes structure and function as it relates to the practice of medicine and other health sciences

Surface anatomy
visualization of the structures that lie beneath the skin

Systemic anatomy
study of body systems

In reference to anatomy and other information a massage therapist needs to know:

Palpation is the forming clinical impression via touch. In addition to muscles and bones, pulses, reflexes, muscle contraction etc. are often palpated to get more information about a client’s condition.

Osteology is the study of bones

Massage Therapy Anatomy Review – Systems of the Body

There are 10 systems in the body.
1. integumentary system – skin and structures within it
2. skeletal – bones and cartilage
3. articular – joints and associated ligaments
4. muscular –
5. nervous – central nervous system (brain and spinal cord), and peripheral nervous system (cranial and spinal nerves)
6. circulatory – cardiovascular (heart and blood vessels) and lymphatic systems (lymphatic vessels and lymph nodes)
7. digestive or alimentary (organs associated with ingestion, digestion, absorption of food and elimination of its associated waste)
8. respiratory – air passages and lungs that supply oxygen to the body and eliminate carbon dioxide
9. urinary – kidneys, ureters, urinary bladder, urethra – which filter the blood and excrete waste (as urine)
10. reproductive – genitals and organs that are involved in reproduction
11. endocrine – glands and specialized cells that secrete horomones

Often the urinary and the reproductive systems are lumped together and are collectively known as the genitourinary system

The Anatomy of Low Back Pain

Understanding the anatomy of the lumbar spine is key to understanding and managing low back pain.

The lumbar spine, commonly called the “low back”, consists of 5 vertebrae, and is located between the thoracic spine (which articulate with ribs) and the sacrum. The vertebrae themselves are given numbers by which they are identified, for example – Lumbar Vertebra 1 = L1, Lumbar Vertebra 2 = L2 and so on.

The normal lordotic curve of the low back is known as a secondary curve, and starts to develop in infancy due to weight bearing caused by learning to sit up and walk.  The low back is especially vulnerable to injury due to its weight bearing task and mobility.

Between each vertebrae throughout the whole spine (except for C1 and C2) is a intervertebral or fibrous disc. The purpose of the disc is to provide cushioning and shock absorption from weight bearing and movement. The intervertebral disc is comprised of the annulous fibrosis and the gel-like centre called the nucleus pulposus – these structures are work together to provide the shock absorption, and are both implicated in disc dysfunction and neurological symptoms.

Facet joints are the articulating surfaces of bone between vertebrae. These synovial joints are known as “plane” joints because their flat surfaces glide over each other. These joints may become inflamed due to injury to the joint or joint capsule itself, or due to compression of the intervertebral discs, forcing them to interact in a “close-packed” position. This close packed position means that the joint surfaces are forced closer together than normal, and will irritate the bone and cartilage during movement as they contact each other and create friction.

During an acute injury, the inflamed tissue in the joints may irritate the nerve roots as they exit the spinal cord via the intervertebral foramina. Eventually, if facet irritation is untreated, bony spurs may develop due to chronic inflammation and cause spinal stenosis – a decrease in the size of the “vertebral foramen” or spinal canal.

In the case of a “bulging” or herniated disc, pressure is exerted on the nerve root as it leaves the spinal cord via the intervertebral foramina. This pinching or pressure on the nerve root will cause sharp, shooting pain, especially when the patient leans forward (flexes) from the hip.  Symptoms will present in the areas that the compromised nerves supply.

© Copyright 2009
www.whymassagetherapy.com
All Rights Reserved.

What is muscular atrophy, and what causes denervation and disuse atrophy?

What does atrophy mean, and what causes atrophy of a muscle?

The definition of Atrophy, according to Human Anatomy and Physiology (8th Edition) is “reduction in size or wasting away of an organ or cell resulting from disease or lack of use”. Atrophy is also referred to as “muscle wasting”.

Atrophy of a muscle can occur in 2 ways – from disuse or denervation.

Disuse atrophy will occur when a person is unable to use a muscle for any number of reasons. It is very common when a limb has been cast from a break or fracture, or a person has been on bed rest for a extended length of time. Once a person is mobile again, or a cast has been removed, the client should undergo a rehabilitation process designed to challenge and strengthen the involved structures. Assuming that the atrophy was only caused by lack of use, the patient will eventually regain strength and normal size of the muscle.

Denervation atrophy occurs when the nerve supply to a muscle is interrupted and the muscle no longer receives signals or stimulus from the nervous system. This type of atrophy can occur from injury to the central nervous system, as in a spinal cord injury, or in the peripheral nervous system, such as a broken bone which damages surrounding nerve. Damage doesn’t necessarily mean a complete severing of the nerve, in which case nerve tissue is not known to regenerate. Damage will occur in varying degrees of severity, and may be a result of compression (impingement), crushing or partial tearing. If this is the case, with proper care and rehabilitation the injury will heal and muscle strength can be regained.

Why is this important to a Massage Therapist?

Massage therapists are specialists in treating the dysfunctions of the musculoskeletal system, and understanding the anatomy of the involved structures is key to providing a successful treatment. Odds are that you will see quite a few conditions throughout your career that will either cause, or have the potential to cause, muscle atrophy. Conditions such as chronic Thoracic Outlet Syndrome or Carpal Tunnel Syndrome may cause denervation atrophy due to impingement or compression of the ulnar nerve root and median nerve respectively, and can be successfully resolved once the underlying cause of the compression has been addressed.

Atrophied tissue is very fragile, and deep techniques are contraindicated until the condition of the tissue improves. Initially, the primary goal of treatment for atrophied tissue is to increase circulation and to stimulate the nerves – this can be accomplished by gentle dry brushing, followed up by light stimulating techniques such as stroking, effleurage or c-scooping. Great care must be taken if there has been crushing or tearing of the nerve, as any local techniques which apply pressure or traction can disrupt the healing of the injury.

It is highly recommended that you consult with the client’s physician, physiotherapist or chiropractor to verify the cause of atrophy, and that you work under his or her supervision and guidance if the atrophy is caused by denervation.

© Copyright 2009
www.whymassagetherapy.com
All Rights Reserved.

Massage Therapy and Anatomy – Arthrology Definition

Arthrology is the study of joints.

Joints occur where the surfaces of 2 or more bones meet. An articulation is another term which refers to a “joint”

Why is arthrology important to massage therapy?

Massage therapists work with the musculoskeletal system. Clients may present with symptoms which may be confusing – it is necessary for a therapist to assess a client’s presentation and form a clinical impression – meaning, his or her opinion on the cause of the symptoms. (remember, massage therapists are not permitted to provide a diagnosis).

Muscles cross joints to produce movement, and any joint dysfunction may lead to muscular imbalance and pain. Muscle tone which doesn’t support a joint (hypotonic – meaning not enough tone), or restricts movement too much (hypertonic – meaning excessive tone), may cause pain in the joint itself.

For a therapist to successfully treat the underlying cause of any symptom, he or she must understand the relationship between muscles and the joints which they cross, as well as the anatomy of the joint itself.

Massage Therapy and Anatomy – C1, C2 and Arthrology

Question of May 8, 2009 – The C1 and C2 vertebrae are considered “atypical”. Why is this, and explain how the 2 vertebrae relate to each other.

C1 and C2 are considered “atypical” cervical vertebrae because their form and function differ from the other 5 cervical vertebrae.

C1, also known as the ‘atlas’, is a circular ring of bone, which consists of anterior and posterior arches and 2 lateral masses. On the superior surface of the lateral masses are the superior articular facets, on which sit the occipital condyles. This allows for a “nodding Yes” motion of the head. On the posterior surface of the anterior arch is the facet for the odontoid process of C2. (see below).

There are no intervertebral discs between C1 and C2.

C2, also known as the ‘axis’, is somewhat similar to other cervical vertebrae, except for the presence of the “dens” or odontoid process – a bony protrusion which projects upward and articulates with the anterior arch of C1. (it is held in place here by the transverse ligament which attaches on both lateral masses of C1). The axis allows for rotation of the head, as in shaking your head “no”

How is this relevant in Massage Therapy? – This is a very vulnerable part of the body, so understanding the anatomical structures in the area is necessary in the case where a therapist may have clients with a WAD injury (whiplash associated disorder). Clients who may have had a bad slip, fall or accident (car or otherwise) in which acceleration/deceleration occured may have the potential for instability in this area. It is important, ergo, for the client’s physician to give a green light for massage therapy treatment, and then for the therapist to proceed carefully.

Question for today (easier today)

What does the term arthrology mean?

Massage Therapy and Anatomy – Cervical Vertebrae C1 & C2

Question of May 5th

Q: If the thoracic and sacral curves are considered primary, what spinal curves are considered secondary? What is a factor in the development of secondary spinal curves?

Answer: The cervical and lumbar lordotic curves are considered secondary. Weight bearing is the main factor in development of these curves – the cervical lordotic curve will develop first as a baby starts to move his or her head; the lumbar lordosis will develop when he or she learns to sit up and starts to bear weight.

Question of the Day
The C1 and C2 vertebrae are considered “atypical”. Why is this, and explain how the 2 vertebrae relate to each other.

Massage Therapy and Anatomy – Secondary Spinal Curves

Question of April 28
What are the 4 spinal curves present in the adult spine? Of these, which are considered “primary” curvatures, and why are they known as this?

A: The four spinal curves present in adults are the cervical, thoracic, lumbar and sacral. Of these 4 curves, both the thoracic and sacral are considered “primary” as they are present at birth.

Question for today:
Q: If the thoracic and sacral curves are considered primary, what spinal curves are considered secondary? What is a factor in the development of secondary spinal curves?

Massage Therapy and Anatomy – Curves of the Spine

Response to question of April 19, 2009

Q: How are the movable vertebrae connected? In addition to movement, what other significant role do they play?

A: Intervertebral discs connect movable vertebrae, and they are also responsible for shock absorption.

Today’s Question:

Q: What are the 4 spinal curves present in the adult spine? Of these, which are considered “primary” curvatures, and why are they known as this?

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