Have you ever wondered why babies suck on their thumbs? Or why chewing crunchy foods helps you study? Or why some students suck on their clothing or chew through pencil tops? Or why some children put non-edible objects in their mouth? Have you ever wondered what ‘chewy tubing’ is and how it works?
Oral motor skills begin developing whilst children are still in the womb. They are born with the reflexive ability to suck, swallow and breathe. Not only does their mouth form a portal for receiving nutrition, but newborns initially learn and explore their environment through their mouths. Babies suck on dummies or their thumb in order to be soothed and calmed. As well all know, children can continue sucking their thumb throughout infancy and early childhood, or they may substitute thumb-sucking for actions like chewing on pencils or sucking on collars and sleeves. But what is the link between sucking/chewing and stress relief?
Chewing is activated by the largest cranial nerve (trigeminal nerve). This nerve has projections that are connected to the parasympathetic nervous system. This is the division of the nervous system responsible for ‘rest and digest’ (ie. Conserving and restoring energy in the body, maintaining and repairing the body) It causes the heart rate to slow, lowers blood pressure and promotes digestion. Have you ever felt the need for a little rest after chewing your way through a particularly large meal?!
The trigeminal nerve also has branches to an area of the brainstem that is responsible for regulating the sleep-wake cycle, alertness and attention (the reticular formation). Chewing on crunchy foods (pretzels, carrot/celery sticks or ice chips are great healthy options) is a great way to improve alertness and concentration. Likewise, drinking from a straw or sports bottle (ie. sucking) will also help to control levels of alertness. Chewing in a rhythmic, repetitive and uniform movement with moderate pressure is linked to activating the reticular formation (think chewing gum or chewy fruit straps).
There are further connections from the reticular formation to an area of the brain which regulates our emotions and behaviour (limbic system). Chewing when angry may act upon the limbic system to help promote calm and stress-relief. It also forms part of the reason why people inhale cigarettes for stress-relief.
Chewing and sucking can form an important part of a child’s self-regulation of anxiety and arousal/attention levels. So instead of trying to get a child to stop sucking their thumb, or chewing their pencils, perhaps replace the behaviours with suitable alternatives. We’ve already mentioned crunchy foods and sippy bottles. There’s also a wide range of food-grade rubber products designed to be chewed (and chewed and chewed!). There’s chewy tubing that can be threaded onto necklaces or onto the ends of pencils, t-bars and chew sticks. And if you’re particularly trendy or worried about chewy tubing making your child stand out from the crowd, then there’s a wide range of chewable jewellery (necklaces, bracelets, pendants) and cute pencil topper designs (that are just as cool as the pencil topper erasers from Smiggle!)
Chewy items have two important functions: they provide direct sensory input and oral stimulation for the mouth (perfect for those kids who put inedible objects in their mouth in order to seek oral stimulation). Chewing provides lots of proprioceptive (body awareness) feedback to satisfy the sensory input that children may be seeking in their mouths. Chewy items also indirectly provide calming and attention regulation through the trigeminal nerve pathways I described earlier. They also save parents from wet sleeves and stretched collars!
Chewy tubing and jewellery is not a cure to promote calming and stress-reduction, but a useful tool that can be part of a greater sensory program (or sensory diet).