Feb 2006 Dalton Newsletter

TMJ and Head-Forward Postures

Erik Dalton, PhD, Certified Advanced Rolfer

A positive test for a head-forward posture requires that the zygomatic arch under the eye be more than 3 centimeters forward of the sternoclavicular joint. Clients presenting with head-forward postures are vulnerable to increased stress not only in the neck but the jaw as well. When assessing and correcting this common postural pattern, therapists should recall that the jaw functions separately from the cranium. Embryologically, the jaw develops from visceral myotomes…not cranial. 

In those with forward head postures, the head and neck moves forward in the sagittal plane causing the brain to backward-bend occiput on atlas. This remarkable proprioceptive reflex (Law of Righting) will cock the head back to level the eyes against the horizon even if it means ravaging the neck.

Regrettably, prolonged head hyperextension causes sustained isometric contraction in the sensitive suboccipital muscles. The suboccipitals actually have no Golgi tendon organs (GTOs) as they attach to the cranium but are loaded instead with an abundant supply of type 3 mechanoreceptors. Type 3 (Golgi end organs) usually found in ligaments, perform identical functions as the tendon organs except they do not respond to contraction by their synergistic stabilizers (muscles performing the same action a given joint.) Therefore, Golgi end organs allow the suboccipitals to maintain proprioceptive balance while other muscles attaching to the occipital ridge continue performing their particular duties.

Sustained isometric contraction in the capital extensor muscles places the entire nervous system in a heightened state of alert. With the head in a forward position, passive tensile forces develop in the hyoid and digastric muscles causing them to shorten, tug on the mandible and translate the jaw posteriorly and inferiorly. Jaw retrusion develops as these tight muscles hold the jaw back as the head translates forward. The temporalis and masseter muscles must now co-contract so the mouth can be kept closed. Prolonged temporalis and masseter contraction promotes abnormal mandibular positioning and disc compression at the temporomandibular joint (TMJ).

 


 

Some common symptoms that typically accompany this strain pattern include:

• Suboccipital pain syndromes
•  Mouth breathing
• Difficulty swallowing
• Teeth clenching
• Face and neck pain
• Migraines  

 

TMJ disruption is notorious for its negative impact on the 11th cranial accessory nerve. Since the upper trapezius and sternomastoids are directly innervated by the 11th cranial, jaw pain neurologically shortens these muscles initiating a “Catch 22” pain cycle. As the upper traps cock the head back and the SCMs pull it forward, excessive tension mounts in the hyoids, digastrics, masseters, and temporalis which, in turn, cause even greater TMJ compression. Optimal head and neck functioning requires that TMJ surfaces retain their ability to glide freely on one another. Since the main innervation to the dural membrane is the vagus and trigeminal nerves, faulty neck and jaw alignment can pinch and twist this sensitive membrane affecting myoskeletal as well as visceral structures. Occipitoatlantal work demonstrated in Myoskeletal Techniques, Volume II videos and Advanced Myoskeletal Techniques home-study course helps therapists relieve 11th accessory and 9th trigeminal pain conditions. Trigeminal nerve treatment should always be complemented with masseter and temporalis work for they are also “up-regulated” in most TMJ/forward head cases.

The Freedom From Pain Institute® offers therapist continuing education through national seminars, state of the art videos and manuals, and certified home study programs.