Physiology: the chewing process - Anatomy and physiology of the head, neck and chewing system
Physiology: the chewing process
To reduce food you make chewing movements. The chewing muscles, the tongue muscles, the suprahyoid muscles and a few mimic muscles work together in these movements. The movements of the lower jaw, cheeks, lips and tongue are coordinated, that is to say coordinated with each other. The collaboration and coordination are called the chewing pattern. The chewing pattern develops after the breakthrough of the first milk elements. When these elements make contact, the cooperation and coordination of all movements during chewing starts. Just as is the case with learning to walk, the chewing movements are not immediately optimally coordinated. Only after a while do the movements take place automatically. The chewing process is partly carried out automatically, or reflexively. All kinds of receptors or sensory organs of mucosa, tongue and periodontium play a role in the chewing process.
As mentioned, the chewing pattern begins to develop at the breakthrough of the first milk elements. After that, it always adapts to the further breakthrough of teeth. Even if the teeth are lost prematurely, the chewing pattern will adapt to the new situation. The chewing pattern is aimed at achieving maximum efficiency with minimal energy consumption. The teeth and molars do not exert more force on the food chunk than necessary. The mouth does not open further than is necessary for the introduction of food.
The chewing movements are not fully automatic. If there is a hard piece in the food, or if an element is painful, for example due to a too high filling, a conscious check of the chewing process will take place. In the chewing process, a distinction is made between free movements and contact movements.
- Free movements are the movements in which the elements of the upper and lower jaw do not touch each other. We make free movements mainly when opening and closing the mouth.
- Contact movements take place when the elements of the upper and lower jaw make (almost) contact. Research shows that our food is 88% soft, 2% brittle, 5% firm and tough and 5% hard and compact. In other words: we only have to chew only a tenth of our food. The majority of our food only needs to be mixed with saliva to be easily swallowed. When consuming hard food, the mass meter and temporalis m on both sides are the most active. On the chew side the muscle activity is greater than on the other side.