2nd… From Out-Thinking… Cranial Nerves … TMJ

FACE

5, 7 TRIGEMINAL NERVE, FACIAL NERVE

Cranial Nerve 5 – “a nerve responsible for sensation in the face and motor functions such as biting and chewing.”

Cranial Nerve 7 – “emerges from the brainstem, controls the muscles of facial expression, and conveys taste sensations from the anterior two-thirds of the tongue and oral cavity.” 

“A blank or expressionless face is one of the classic signs of Parkinson’s Disease, used as a principle diagnostic point by neurologists. If this is allowed to progress, the face can take on a “plastic mask” appearance: featureless (puffy), with a “waxy” or shiny appearance. Problems chewing, over-clenching and misalignment of the jaw are common symptoms too. Indeed, temporomandibular joint (TMJ) disorders are strongly correlated with PD.”

(I have extracted what follows from the preceding link on TMJ) TMJ was one of the reasons I have struggled to eat… but until now, I did not understand the correlation.

“A systematic review by Medlicott and Harris found that active exercise, manual mobilizations and postural training may be effective in treating temporomandibular joint (TMJ) disorders.1 However, many therapists choose not to treat the condition unless the client is experiencing pain. I believe this represents a missed opportunity to address anatomical and functional problems in their early stages.”

“When the head and neck move forward in the sagittal plane, the brain’s visual proprioceptors cause the occiput to backward-bend on atlas. This remarkable brain stem reflex (Law of Righting) will cock the head back to level the eyes against the horizon even if it means ravaging the neck.” 

“Sustained isometric contraction in the suboccipitals reflexively weakens the longus capitis and colli antagonist muscles and places the entire nervous system in a heightened state of alert. With the head and neck jutted forward, passive tensile forces develop in the hyoid and digastric muscles.”

……………………..The brain, in essence, is trying to compensate for the forward head carriage by pulling back on the cranium using the jaw muscles