Treatment of TMD with the Molar Lever

The harder you clench... the further you stretch the TMJ

The Molar Lever at work: the harder you clench… the further you stretch the TMJ.

EXECUTIVE SUMMARY

In this post, we  describe our understanding of how it is possible to treat Temporomandibular Joint Disfunction (TMD) with a splint therapy based on the principle of the Molar Lever.

We base our reasoning on the empirical observation of the results of the clinical trials carried out for over two years on patients using the Starecta protocol to straighten their spine using the Rectifier, a modified Gelb lower dental splint that produces orthopedic forces based on the principle of the Molar Lever.

We conclude that by using a splint that reestablishes the natural lever bio-mechanics of the mandible on the dental arches it is possible to relieve pressure, unjam and recapture the healthy position of the condylar disk of the TMJ.

Specifically, by establishing a fulcrum between the distal lingual cusps of first molars and lower second molars (as described in the picture above) it is possible to activate a biomechanical lever that stretches and unjams the TMJ as we contract the masticatory muscles.

Therefore, we can use a splint to reestablish a natural mechanism (which, in healthy natural mouths never touched by a dentist is based on a pronounced curve of Spee and sound condylar shaped molar cusp-fossa relations) to bring about the result that:

The harder the patient clenches… the further the TMJ stretches, unjams and relaxes

What is TMD?

Temporomandibular joint dysfunction (TMD) is an umbrella term covering pain and dysfunction of the muscles of mastication (the muscles that move the jaw) and the temporomandibular joints (the joints which connect the mandible to the skull).

TMJimage

The most important feature is pain, followed by restricted mandibular movement, and noises from  TMJ during jaw movement. This noises are usually related to the rapid reduction of the fibrous disc malpositioned between the condylar head and the glenoid fossa.

TMD / TMJ , Dystonia and Neurological Symptoms

The derangement of the Temporomandibular Joint (TMJ) has been associated to neurological symptoms and neurological movement disorders like Dystonia, Tourette’s and Parkinson’s, as well as chronic pain conditions like Occipital Neuralgia.

image

Torsion of the spine, scoliosis, neurological movement disorders, etc. happen when ONE CONDYLAR DISK IS ATERIORLY DISPLACED AND THE OTHER IS POSTERIORLY DISPLACED.

The pioneers of the bio-mechanical approach to complex neurlogical syndromes (Dr. Stack, Dr. Brown and Dr. Lee) treat those conditions by using different kinds of removable dental appliances to realign the TMJ, the mandible and the skull and recover a healthy position of the articular disk within the TMJ. As you can appreciate in the clinical cases that we have included in the Resources page of this blog, they consistently achieved remission or discontinuance of neurological symptoms with their approach.

wpid-screenshot_2015-10-20-12-23-15-1.png

As our readers can appreciate in the post dedicated to A Bio-Mechanical Approach to Cervical Dystonia, we consider that the main factor triggering neurological symptoms is the compression of the brain stem at the upper cervical level (between C1 – the Atlas- and C2 – the Axis). Our approach is not radically different from the one put forward by Dr. Stack, Dr. Brown and Dr. Lee as – and it will be clear at the en of this post – the alignment of the upper cervical vertebrae and the TMJ are concurrent effects of the same splint therapy.

wpid-screenshot_2015-10-20-12-22-44-1.png

Treatment of TMD

TMD is a symptom complex rather than a single condition, and it is thought to be caused by multiple factors. However, these factors are poorly understood, and there is disagreement as to their relative importance.

There are many treatments available, although there is a general lack of evidence for any treatment in TMD, and no widely accepted treatment protocol exists. Common treatments that are used include provision of occlusal splints, psychosocial interventions like cognitive behavioral therapy, and medications like analgesics (pain killers), Botox injections or others.

A New Paradigm

The contents of this post are the results of finding an answer to a simple question:

Why do people using the Starecta protocol do not incur in  TMJ pain or derangement as they build their own splints with extremely high (up to 10 mm) vertical dimension, in multiple and very different positions of the mandible with respect to the skull and producing extremely strong muscular activity of chewing muscles ?

The question is relevant, specially when we take into account the fact that many experts  argue that to treat TMD is necessary to do exactly the opposite:

  • Some experts use very sophisticated technical equipment (to measure muscle activity, position of the condyles, etc.) to find ONE perfect position  of the mandible and the condyles where condyles can move with a purely rotating “hinge” motion that will reduce to a minimum muscle activity. It is the opposite of the multiple positions of Starecta splint bite registration.
  • Other experts prescribe an extremely precise construction of occlusal contacts to avoid interference and noxious propioceptive sensory input. This micro-occlusion approach is the opposite of the macro-occlusion imprecise and partial coverage approach of the DYO (do it your-own) homemade splints of Starecta.
  • Other experts recommend the reduction to the minimum of muscular activity (even by using Botox injections to paralyze specific muscles). That is the opposite of extreme muscular forces that the Rectifier stimulate and uses to transfer orthopedic forces to the upper cervical spine.
  • Some other experts recomend an upper flat plane splint (a Michigan splint) which is the opposite of the lower, partial coverage Rectifier with deep pits on lower molars to embrace upper molar cusps in a rock solid position.
  • Some more experts recommend equilibration to flatten the Curve of Spee by reducing the size and contacts between opposing dental cusps. That again is the opposite of the quintesencial principle of the Rectifier that is establishing a higher point of dental contact (where big upper cusps are fully embraned by lower deep pits)  that acts as fulcrum to allow the mandible to pivot during clenching.
  • The great majority of experts defend that it is necessary to build an orthotic splint on an external model of the mouth build on an articulator. That is the opposite of the Starecta protocol based on the registration of bites on a splint directly in the patient’s mouth.

How does the Molar Lever Work?

In a previous post, thoroughly described the principle of the Molar Lever and how we apply it to build a dental splint that produces orthopedic forces that use lever mechanics to transfer the force of th masticatory muscle to fuel a stretching force in the upper cervical vertebrae. In this post we will briefly summurize it.

In the next two pictures tou can se how the Molar Lever works:

image

By applying force with the hand along the same direction that the masticatory muscles do (red arrows in the picture), you can clearly appreciate how – as the mouth closes – the posterior part of the mouth is subject to a stretching force (green arrows in the picture): the white plastic sustainers slide along the rails and the distance between the mandible and the maxilla in the back side of the mouth is raised about half a cm.

molarlever

That is how the lever centered along the molar part of the dental arches stretches the back of the cervical spine and lifts the skull.

image

Thus, the masticatory muscles transfer their grinding force by means of a bio-mechanical lever to the cervical spine,  stretching it and elevating the skull.

image

The Molar Lever is the fundamental orthopedic force that the Rectifier uses to progressively and gradually stretch and recover verticality of the spine.

The next picture shows how using a splint based in the principle of the molar lever can straighten the spine in a period of 1 year.

image

And the following picture shows RX evidence of the effects on the upper cervical vertebrae of one year of  therapy carried out with a splint based on the molar lever principle.

wpid-1620487_607818232631326_617798102_n.jpg

How does the Molar Lever act on the TMJ?

When we build a lower dental splint that establishes a curve  that acts as fulcrum between the distal lingual cusps of first molars and lower second molars (as described in the picture below) it is possible to activate a biomechanical lever that stretches and unjams the TMJ as we contract the masticatory muscles.

TMD molar lever

Therefore, we can use a splint to reestablish a natural mechanism (which, in healthy natural mouths never touched by a dentist is based on a pronounced curve of Spee and sound condylar shaped molar cusp-fossa relations) to bring about the result that:

The harder the patient clenches… the further the TMJ stretches, unjams and relaxes

The stretching force the acts on the TMJs allows for the reduction of pressure on the TMJs, by increasing the distance between the glenoid fossa and the head of the condyle. Thus, it allows the circulation od sinovial fluid, it creates the conditions necessary to reduce the inflammation of the joint and favours the recapture of an anteriorly displaced condylar disk towards a healhty physiological position.

It is worth noticing that the very same concept is used by the Gelb protocol of splint therapy. There is massive scientific academic literaure that proves the effectivenes of the Gelb lower splint in recapturing the malpositioned condylar disks.

Is Clenching Good or Bad?

Patients are often diagnosed as “suffering” from pathologic Bruxism and Clenching and receive treatments to reduce the daytime or nightime activity of masticatory muscles. The evidence and analysis that we produced above forces a reflection on those concepts. Is clenching pahtologic in the greater scheeme of things?

Our analysis seems to suggest that clenhing is a necessary and positive natural reflex and that it becames pahtologic and produces adverse effects, inflammation and jamming on the TMJ if (and only if) the natural curves of the mouth that create a bio-machanicallever have been impaired and flattened by trauma or iatrogenic damage.

We can observe in the picture below a comparison between a natural healthy outh never touched by a dentist and the mouth which is the result of multiple intervetions by trauma, time, aging and dentists.

Natural healhty mouth nevert ouched by a dentist compared to one treated by dentists

Natural healhty mouth nevert ouched by a dentist compared to one treated by dentists

We can observe that the natural healthy mouth never touched by a dentist (right in the picture above) has a very pronounced curve of Spee that allows for the natural functioning of a bio-mechanical molar lever effect.

The picture below shows how a healthy and pronunced curve of Spee can create a natural molar lever effect to offload the TMJ when the patient clenches.

A natural healthy and pronounced curve of Spee creates a molar lever effect that offloads the TMJ when the patient clenches

A natural healthy and pronounced curve of Spee creates a molar lever effect that offloads the TMJ when the patient clenches

 
 
 

Navigate Through this Blog

To further understand our reasearch, approach and method, please read:

A Bio-Mechanical Approach to Dystonia
An introduction to the theory and analysis that support the pilot research project to use an adaptive intraoral appliance to treat and possibly cure Secondary Idiopatic Cervical Dystonia.

Principles of Splint Therapy
A description of the principles on which we base our protocol for the treatment of Cervical Dystonia and other occlusion realated movement disorders with varying degrees of neurological symptoms (from Tourette’s, to postural collapse, Parkinson’s and Generalized Dystonia).

Protocol for the Treatment of Cervical Dystonia
A step by step description of the 3 phases of the DIY protocol that we have developed for the treatment of Cervical Dystonia.

The Molar Lever
Our analysis of the bio-machinics of the Molar Lever and how dental occlusion is related to posture and skeletal allignment.>

Phases of Lateral Postural Colapse
Our analysis of the descending skeletal and postural effects of a collapsing and twisting skull that does not find adequate support in the dental arches.

The Rectifier
A description of the adaptive intra-oral aplliance -dental splint – that we use to treat Cervical Dystonia and the orthopedic forces that it produces by progressively pushing the mandible in retrusion, maxila in extrusion and elevating the skull by stretching and aligning the cervical vertebrae.

Resources
Bibliography and links to scientific research on the treatment of Dystonia and other neurological movement disorders with a bio-mechanical approach.

Postural Colapse and Dental Arches
A set of animations that present grafically the type of skeletal and postural effects that we intend to produce over a few months by modifying occlusion and the direction of forces between the skull and the mandible.

6 thoughts on “Treatment of TMD with the Molar Lever

  1. Marcello, your explanation of the “curve of spee” is what I have been experiencing with my occlusion since integrating starecta 31/2 months ago. Thank you for taking the time to put this explanation together. I had trouble explaining it to friends but now I can send them the link. thank you, Armando

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    • My pleasure Armando. Thanks for your comment. As a matter of fact, one of the reasons I wrote this post is to have a link to send to all those people who could benefit from a self made splint but do not have severe neurological symptoms like Dystonia.

      Like

  2. Pingback: Äntligen fattar jag hur skenan funkar och hur tungan ska kännas | 15monthslater

  3. Pingback: Protocol for the Treatment of Cervical Dystonia | Bio-Mechanical Dystonia

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