The simple act of eating involves the tongue in two ways. It allows on the one hand to pre-digest foods by chewing them and insalivating them, and on the other hand to swallow to send the food bowl into the oesophagus while protecting the aerodigestive crossroads from any risk of inhalation at the resumption of breathing, hence the importance of having a good lingual competence. A person who swallows by sucking, that is, who continues to swallow as if they were suckling a nipple, has not developed the habit of chewing food properly. She generally adapts her diet accordingly, with soft foods, which do not need to be chewed, and may therefore have difficulty digesting; the risks of false roads are greater.
During chewing, the role of the tongue is to move food from right to left to allow the molars to crush it. This action of the tongue also allows to mix the food bowl of saliva and thus to prepare the digestion. This chewing action requires a good occlusion (teeth that are well “arranged” and mesh perfectly). The pressure of the upper teeth on the lower teeth during chewing strengthens their implantation and balance in the jaws.
Is the act of swallowing. This applies to both saliva and food. During swallowing, our tongue increases its support to the palate for a fraction of a second. This swallowing action is performed nearly 1500 times a day for saliva, including at night!
Swallowing is different depending on the feeding mode (liquid at first): the baby does not swallow in the same way as the young child or adult.
To feed, the baby starts a sucking process. He tightens the nipple with his lips, contracts the cheeks and chin to make the mouth airtight, presses the nipple with his tongue against the upper gum and palate, and sucks in the milk. This process is called “infant swallowing” because it only affects babies and young children. During the foetal period, the baby already trains him to suck in his mother’s womb and continuously swallows the amniotic fluid. Swallowing for children is perfectly natural for absorbing liquid food, but should not last longer than 7 years.
Mature swallowing is the natural evolution of infant swallowing. As soon as the child is fed a solid diet (around 2 years old, and systematically after 7 years), he can no longer simply suck up the food: he must then chew it, then chew it.
The tongue is used to transport food from right to left to allow chewing on both sides. It is flat, flexible in its middle to collect the food bowl or saliva, spread along the molars. When swallowing, the mouth is closed, the teeth are clenched and the lips are soft. Clamping the teeth helps to stabilize the mandible and ensure that the upper and lower teeth mesh properly. It is a factor for the harmonious growth of the jaws. The tip of the tongue rests just behind the upper incisors and rises like a wave to tip its contents towards the throat.
When the infant swallowing reflex persists beyond the age of 7, it is called “atypical” or dysfunctional swallowing.
It is often maintained by regular and prolonged use of pacifiers, bottles and any other sucking object including the thumb. This type of swallowing is favoured by a soft diet (purées, pasta, soft breads, minced meat, etc…) or drinks drunk with a straw. These behaviours and eating do not encourage the child to evolve towards a mature swallowing and he becomes an adult while maintaining his dysfunction.
Atypical swallowing is a lingual dysfunction that is identified by the contraction of the chin and lip muscles during swallowing, like the baby who is suckling. The tongue comes between the lower and upper teeth, preventing them from being clenched as they should be. The child or adult moistens the food with saliva and then crushes it with his tongue, which makes forward and backward movements against the palate and finally swallows the tablets on the teeth: although he has teeth, he always swallows by suction.
Mr. Vanpoulle talks about “molarization of lingual function”. Indeed, the tongue thus compensates for the lack of crushing of the food bowl normally produced by the molars.
Impacts on food and health
When food is not sufficiently chewed, the pre-digestive salivary action does not work properly and digestive functions are more than naturally solicited.
Since the tongue is so important for chewing and swallowing functions, it is easy to understand that a lingual dysfunction causes difficulties in eating. In the long term, the lack of chewing and atypical swallowing has important repercussions on tooth implantation, facial development or head posture and indirectly on the body.
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