We’ve been looking at the four domains of feeding we consider in our initial assessment, including feeding skills. Last time we looked at the importance of the lips. This time, we’ll be looking at the jaw.
So…how do we move our jaw?
The movement of our jaw is primarily controlled by one of our cranial nerves – cranial nerve 5, otherwise known as the ‘trigeminal nerve’. The trigeminal nerve controls the important muscles we use for chewing. Here’s some of the key ones:
Three muscles under your chin allow you to open your jaw – one of which we particularly like the name of – the ‘anterior belly of the digastric’
Two large muscles – the ‘masseter’ and ‘temporalis’ allow you to close your jaw.
When it comes to chewing your food – the muscles on either side of your jaw – the right and left ‘pterygoids’ – alternate to achieve a rotary chewing action, moving your jaw in a circular motion.
Why is our jaw so important for eating and drinking?
The muscles that move your jaw:
Allow you to open your mouth to get the food and drink in – this is especially important when you are taking a big bite of something like a hamburger (yum!).
Keep your mouth closed when chewing to prevent food or drink falling out.
Allow you to chew your food to a consistency so it’s safe to swallow – we’ve all had that bit of corn chip that’s escaped without being fully chewed, ouch!
The masseter muscle in particular – your cheek muscle – is also really important during chewing as this helps to push food out of your cheek and back into your mouth to ensure it is chewed properly and prevent a build-up of food in your cheek.
Difficultly chewing may look like a preference for softer foods, such as yoghurt, soft fruits, soft chips (such as pea snaps) that melt in the mouth, and an avoidance of hard crunchy things like biscuits, crackers, toast, hard fruits and vegetables and chewy food such as meat.
If this is something you have noticed, and it’s happening alongside stressful meal-times, feel free to get in touch as we may be able to help!
So… next time you enjoy a delicious hamburger you can thank your trigeminal nerve!
