Monday, 27 October 2014

Medial & Lateral Pterygoids

I almost forgot about these two lil' jaw muscles! The medial and lateral pterygoids -
(pronounced: terra-goids) These two assist the massester and temporalis muscles in movement of the jaw bone (aka mandible). All four of these muscle together can be considered 
"the muscles of mastication" (mastication is a fancy word for chewing!)

Medial Pterygoid:

located on the inside of the jaw and looks a lot like masseter (shaper, muscle fiber direction..)
It's position basically mirroring masseter - it's just on the inside!

FEEL medial pterygoid by digging your thumb (gently!) under the angle of your mandible (jaw!)
once your in there - clench your jaw to feel it contract! (aka elevation of the mandible)

  Official Attachment points: 

Origin:  sphenoid bone and maxilla (bones on front of skull - see pic below :)
Insertion:  medial surface of ramus of mandible (inside the jaw - below your ear)

 Medial Pterygoid Muscle Actions: 

Unilaterally (one side only) : a) laterally deviates the mandible to the opposite side
Bilaterally (both sides together) : b) assists in elevating the mandible.
(aka clenching your jaw or closing your mouth (from open position

c) protracts the mandible (aka protraction)

Lateral Deviation - left right left right!

(besides my crooked bottom teeth ;) NOTICE how I can laterally deviate further in one direction than the other? No bueno! 

(this is a mirror image - I cannot laterally deviate to LEFT side as far as I can to the Right -  indicating a possible issue with the pterygoids on the opposite (RIGHT) side.) 

 okay now:
 Lateral Pterygoid

Whereas the medial pterygoid's muscle fiber direction is vertical, Lateral Pterygoind's fiber direction is horizontal.

Official Attachment points: 

Origin: two separate points on the sphenoid bone 
(up in your head)
Insertion:  temporo-mandibular joint (TMJ)
Lateral Pterygoid Muscle Actions:

Unilaterally (one side only) : a) laterally deviates the mandible to the opposite side
Bilaterally (both sides together) : b)  protracts the mandible 
(aka protraction - basically jutting your chin out!)

Go ahead and try it! Discomfort ? There's a massage therapy treatment for that! 
Certain parts of each pterygoid are accessible inside and outside the mouth.

Most often I treat jaw tension from the outside  but did you know we can throw on a surgical glove and work the muscles intra-orally too ? Believe it.

Lots of us have jaw tension and it can be on one side or both - many of us clench our jaws when we're stressed and sometimes even clench overnight.   Try a jaw massage sometime - you'll be pleasantly surprised how you feel after :)