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Technique: TMJ Mastery part 3

This is the final installment in our three-part series exploring principles and concepts of intra-oral applications for the treatment of TMJ dysfunction.


September 15, 2009
By john w. corry rmt

Topics

This is the final installment in our three-part series exploring principles and concepts of intra-oral applications for the treatment of TMJ dysfunction.

In this final article, focus is given to the Articular Disc and the progressive scenario of disc displacement, along with some discussion regarding whether or not the presenting stage is retrievable.

As well, access and treatment of the Lateral Pterygoid Muscles is depicted along with TMJ decompression mobilization.

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 Fig 1: Right Articular Disc


 

Joint Noise: An Articular Disc Calling For Help
A temporomandibular joint that emits noise with movement such as clicking, popping, grinding, or clunking is likely experiencing either a partial or complete Articular Disc displacement.

The intent of treatment is to restore balance of the anterior/posterior pulling forces on the disc. This is accomplished by decompression of the TM joints, and effective reduction of the hypertonicity of the Lateral Pterygoid muscle group. An environment is then created that invites the Articular Disc to restore its correct position on top of the condyle. 

Viewed laterally, the disc has three named areas – the Posterior Border (PB) and Anterior Border (AB), and an Intermediate Zone (IZ) in between (Figure 1). The Intermediate Zone is an important point of reference as it is the area upon which the condyle remains in “contact” during opening and closing – in a normal functioning joint.

What Holds The Articular Disc In Place?
The disc is held on top of the condyle predominantly by its bi-concave shape. This gel-ball like structure is composed of dense fibrous connective tissue and void of any blood vessels or nerves. The thick anterior and posterior borders provide a self-positioning feature.

There are two distinct synovial joint cavities above and below the disc making it truly a compound joint 1.  Ligaments wrap the disc medially and laterally and contribute to its correct position. This is called the Condyle-Disc Complex. In the normal joint the whole complex moves as one on the mandibular fossa above.

A unique blend of forces is employed to further keep the disc correctly positioned during movement; at the posterior aspect of the disc are the Superior and Inferior Retrodiscal Lamina (see figure 2; SRL & LRL). When stretched upon opening the laminae provide retraction forces to bring the disc back with
the condyle. On the anterior aspect of the disc is the 40 per cent of Superior Lateral Pterygoid (SLP) muscle that inserts on the disc.

During the power-stroke (chewing on food or clenching), the SLP matches the retraction forces of the posterior laminae, and if the ligaments and shape are uncompromised, the balance of forces is maintained and the disc remains in place.

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 Fig 2:  Lateral View of Right TMJ


 

  • SLP – Superior Lateral Pterygoid muscle
  • ILP  –  Inferior Lateral Pterygoid muscle
  • SRL – Superior Retrodiscal Lamina (elastic)
  • IRL –  Inferior Retrodiscal Lamina (collagenous)
  • ACL – Anterior Capsular Ligament
  • AS – Articular Surface of Mandibular Fossa
  • SC – Superior Joint Cavity
  • IC – Inferior Joint Cavity
  • RT  – Retrodiscal Tissue – highly vascularize and innervated
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Figure 3: Condyle Shown Pressing on Posterior Border of Anteriorly Positioned Articular Disc


 

The Continuum of Disc Dysfunction   Stage One Internal Derangement: 
If the morphology of the disc is altered or discal ligaments become elongated from direct or indirect trauma, a progressive scenario is initiated allowing the
disc to begin a dysfunctional position2. A major factor in this scenario is the tone of the SLP muscle. Once discal ligament elongation is present, a hypertonic SLP will “win” over the Retrodiscal Laminae, and the disc will begin to translate forward thus announcing the first stage of disc displacement. Upon opening the disc bunches as the condyle passes the Posterior Border on the way to the Intermediate Zone (IZ), resulting in a click. At this stage, the Posterior Border is receiving compressive forces and thinning begins. Once the condyle has clicked and the IZ has been reached, normal condyle-disc positioning remains throughout opening and closing.

Stage Two Reciprocal Click:
After a period of time the Posterior Border continues to thin and its self-positioning feature starts to break down. The first click upon opening restores the IZ/condyle relationship. However, as the jaw closes to rest the thinner PB allows the hypertonic SLP to pull the disc further forward and a second click can be heard. During rest the disc is now resting far enough forward to allow the condyle to press on the Superior and Inferior Retrodiscal Lamina, which is not constructed to receive such forces and ischemic degeneration begins.

Stage Three Functional Dislocation of the Disc with Reduction:
Without treatment, the disc progressively migrates forward enough for the condyle to be completely behind it, resulting in the collapse of the discal space. Now the disc is beyond mere displacement and, therefore, this stage is acknowledged as a disc dislocation. Joint sounds are silenced because no Posterior Border skidding and bunching can occur upon opening. Some clients are able to employ lateral and protrusive mandibular movements to force the condyle over the Posterior Border and onto the disc, known as a joint reduction.
 
Stage Four Functional Dislocation without Reduction:
In time, the client’s restorative attempts fail to get the condyle over the Posterior Border. The disc itself can be perforated and begin to breakdown. The discal ligaments are compromised enough that they and the Retrodiscal Laminae are a source of pain and inflammation, known as Retrodiscitis. The condyle and mandibular fossa are now in such a position as to allow Osteoarthritis to begin.

Early Intervention
Clearly, this continuum presents a scenario in which early intervention is extremely valuable. If the stages are allowed to progress, the possibility of reversing the continuum becomes less feasible. Even judging the stage of the continuum is admittedly difficult as it requires one to visualize what the disc is doing according to the timing of the sounds heard during opening and closing. Having an MRI machine at our disposal would be optimal, but short of that the following guidelines have been generated from experience.

If a click is heard upon each opening (Stage 1), or even an additional reciprocal click when the jaw closes to rest (Stage 2), there is a chance that decompressing the joint space and resolving the asymmetrical hypertonicity may invite the disc to return to its correct position – with the condyle and Intermediate Zone in proximity.  However, the longevity of this restoration varies.

Bear in mind that if the disc is dislocated (Stage 3 & 4) the client is faced with a situation where treatment becomes a management resource. For all stages this includes re-establishing the joint space and accessing the Lateral Pterygoid muscles to influence their desire to “win” and pull the disc forward.

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Figure 4: Orientation of Palpation of Lateral Pterygoid group


 

Accessing The Lateral Pterygoid Muscles
The mere idea of accessing and affecting the Lateral Pterygoid muscles is controversial. However, the superior palpation skills of a RMT have transcended the predictions of many textbooks.

For example, Dr. Hoppenfeld in his Physical Examination of the Spine and Extremities states that the Levator Scapula muscle is “not palpable.”3 Obviously, Dr. Hoppenfeld hasn’t met too many well-trained RMTs!

Correct technique, intent of the practitioner along with a strong knowledge of anatomy, ensures that the Lateral Pterygoid muscles are palpable through the superior portion of the Medial Pterygoid muscle, similar to the palpation of the Levator scapula muscle through the Upper Trapezius muscle. Fortunately, the client can feel a very different sensation between palpation of the Medial and Lateral Pterygoid muscles, and can therefore confirm the palpation. The orientation of the gloved index finger is shown schematically in Figure 4.

In Part 2, access of the Medial Pterygoid muscle was discussed and the access of its Lateral deeper cousin is a simple shift upwards. Instead of initiating access between the teeth, begin by running along the inside edge of the upper row of teeth.

The Pterygomandibular Raphe presents the same bony landmark before continuing posteriorly and superiorly. As you roll upward and backward, the client may have to open slightly, momentarily employing the Inferior Lateral Pterygoid.

This recruitment often helps to confirm the palpation. Treatment is initiated by flexing the DIP joint of the finger and having a conversation for five to 15 seconds with any resistance found in the Lateral Pterygoid muscles. Repeating this alternately from side to side will accumulate a release of the hypertonicity.

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Figure 5: Accessing the Lateral Pterygoid group requires a small supination roll of the hand as the gloved finger travels along inside edge of upper teeth.


 
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Decompression Mobilization; Direction Of Force


 
   

Decompression Mobilization
By amalgamating myofascial treatment of the Temporalis muscle, effective treatment of the muscles of the Mandibular Sling, and the treatment of the Lateral Pterygoid muscles, it is possible to re-establish the joint space. The next step is to offer the client a “partner-stretch” to the TM joints. Both left and right sides may benefit from decompression eventually, but start with the side exhibiting the most delayed condylar movement. 

Some clients will present with a TM joint anomaly characterized by a squared articular eminence that renders decompression mobilizations contraindicated. They will have a history of avoiding full opening and often their dentist will have seen the anomaly on x-ray. These clients present with an actual condylar subluxation upon full opening, and given their joint laxity are very guarded.

For safe candidates, placing a gloved thumb on the lower rear molar positions the hand for a technique described as “downwards thumb – chin lift” (figure 5). Many clients will want to open slightly thinking they must spare your thumb from danger.

However, it is essential that they rest their teeth on your thumb as any employment of mastication muscles sabotages the correct line of joint tractioning – seen in blue in the photograph above.

Remember a release is accomplished by repetition, not duration, therefore repeating three or five times is more effective than sustained pressure. Palpate the joint space with the outer hand during the decompression to determine the correct amount of force for each client.

Apply gradually increasing forces downward on the rear lower molar – sustain the force for a few seconds as the joint space opens slightly to an “end feel” – and then gradually ease the force to 10 per cent. Mobilizations should always be delivered with gradual forces, never abrupt. Take the time to explain what to expect and that they are the boss and can say “stop” anytime. Some apprehension is common the first time a client receives this technique, but within a few experiences they should gain confidence and allow the joint to receive this valuable dose of space-making decompression.

Series Summary
The massage therapist who possesses skills for treating TMJ dysfunction establishes a niche among their peers. While clients with physical trauma will certainly need this work, new markets become available given many actors, teachers, clergy, broadcasters, singers, brass and woodwind musicians find accumulated TMJ dysfunction greatly influences their voice quality or embouchure.

As well, psychotherapists will acknowledge the value of the jaw being the area through which people express or withhold feelings and needs. The TMJ work may offer a link in this mind/body connection, and networking with talk-therapy practitioners is therefore mutually valuable.

Every case will arrive with subjective combinations of pain, asymmetrical mechanics, and possibly disc displacement noises which can be a daunting array of issues to figure out. Assessing the TMJ dysfunction with a focus of “which condyle is delayed,” provides both a point of reference for assessment and a criterion to measure success. Ultimately, if clients can re-pattern their clenching habits toward “lips closed – teeth open,” especially during sleep, a great deal of TMJ dysfunction can be resolved.

It is imperative to acknowledge that the symmetry and function of the cranial bones, and the dental occlusion issues play a role in the overall TMJ function. The applications depicted in this three-part series present a contribution to the whole Craniomandibular Complex – a contribution that is often overlooked. For many clients, the pain of TMJ dysfunction is difficult to “move to the back burner.” It robs vitality, patience, powers of concentration and sleep depth, and can greatly affect a person’s quality of life. Consequently, even if it is not possible to fully resolve the TMJ issues, making a more manageable scenario is often highly valuable.

References
Figures 1, 2 and 3 were reproduced with kind permission by the author and publisher of Management of Temporomandibular Disorders and Occlusion, 5th Edition. Many thanks to Dr. Jeffrey Okeson, Mosby Publishers, and illustrator Allison Lucas Wright.

1. Okeson, Jeffrey P: Management of Temporomandibular Disorders and Occlusion, 5th Edition: Lexington, Kentucky, 2003.  p. 9
2. Ibid. P. 213
3. Hoppenfeld, Stanley; Physical Examination of the Spine and Extremities, p. 121

john-corry-headshot  
 John W. Corry, RMT


 

Biography
John Corry graduated in 1989 from Sutherland-Chan School and Teaching Clinic in Toronto. He has been a Treatments & Techniques instructor delivering the Ontario 2200-hour program, has presented at workshops and international fitness conferences, and has been a career-long member of the Ontario Massage Therapists Association, twice being a local chapter president. He pursues a level of excellence in innovative applications, and started focusing on TMJ cases
in 1992. He facilitates a three-day instructional workshop called TMJ Mastery and works at Wholisitc Body & Baby in London, Ontario. Contact John at: tmjmastery@hotmail.com


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