The clinical aspects of tongue posture
Importance of nose breathing:
Dentists and orthodontists are fully aware that successful and attractive facial development is only possible in children who breathe through the nose, using mouth breathing only as an emergency 'top-up' system. The group of muscles that plays the greatest role in the development of nose breathing is that group of muscles that move or change the shape of the tongue.
When these muscles operate in an efficient and balanced way not only is nose breathing the most comfortable way to breathe, swallowing, speaking and singing also develop natural efficiency and the lower teeth are found to be in a good relationship with the upper teeth both for chewing and when at rest.
To understand how to simply and quickly change a poor tongue position into a good one it is necessary to know that the tongue has two different kinds of muscle responsible for two different actions.
The intrinsic tongue muscles that form the tongue shape:
These are involuntary. We access them through the right hemisphere of the brain, which is responsible for learned reflex patterns, the imagination and a sense of play. The intrinsic muscles of the tongue change the shape of the vowels in speech. They also push food between the teeth during chewing. If we were in control of that we would continually bite our tongues!
The extrinsic tongue muscles that enable us to put the tongue out, pull it back and down and pull it back and up
They rise in structures away from the tongue and insert into the tongue shape. They are voluntary - we access them through the left brain hemisphere, which is also responsible for most of the other functional things we do.
Appliances for changing tongue position:
Many and varied devices in both hard and soft materials have been designed to exercise muscles to change the position of the tongue in the mouth and change mouth breathing to nose breathing.
What is the difference in position that these devices are trying to achieve?
If the tongue lies flat in the floor of the mouth with the tip against the bottom teeth you will breathe through the mouth every time you open it, and you open it to talk. For the tongue to facilitate nose breathing in all situations it must rest against the palate and not in contact with the lower teeth. This will facilitate nose breathing whether the mouth is open or closed.
Some clinicians advocate sealing the lips at all times when not speaking or eating, but the danger in training for lip seal is to limit communication, which is one of the fundamental evolutionary drives of Homo sapiens. This is working against natural forces, thus making change much more difficult.
All creatures before Homo Sapiens had the tongue in the floor of the mouth (see the picture of the chimp below) and a high arched palate. When evolution added speech to supersede chewing, the tongue had to dramatically change its position and the palate had to change to the shape of a spring board.
Our nearest ancestor, the chimp, has a very high larynx. It is suspended from a hyoid bone that rests just behind the mouth and because the tongue rises from the hyoid bone the whole tongue is forced to occupy the mouth, the front pressed against the front teeth. Although the chimp can be taught all of the vowels that we can make, the high larynx and flat tongue cannot make consonants because for that you need to be able to spring the tongue backwards or off a wide flat surface.
This is only possible if the palate changes shape, the larynx moves to a much lower position in the pharynx and the tongue takes up the position of a right angle, with its main weight and bulk in the pharynx and only one third in the mouth. This one third then bounces off the hard palate, gradually changing the gene structure to flatten the palate so that its shape encourages the tongue to form a wedge at the back of the mouth from where it can spring both forwards into a tip, and backwards into a stronger wider wedge.
This also serves as a brace against the soft palate to seal off the mouth and allow only nose breathing when the mouth is open for communication.
The chimp's flat tongue...
...produces a high, narrow arch.
This tongue position stimulates the soft palate to pull laterally as well as elevate, thus activating the muscle that links it to the Eustachian tubes (Tensor Palatin). When a child speaks or sings using this back spring of the tongue the Eustachian tubes are pumped by the rhythmic action of the vocal mechanism. Provided there is sufficient encouragement to speak and sing using the tongue in this good way this child is unlikely to suffer middle ear infection.
This shift of the tongue should occur in every child between the ages of two and six years old and therefore should be completed before the onset of mixed dentition. The maturation of the central nervous system at approximately seven to eight years old 'cooks' this early developmental information, which can then be accessed for sophisticated learning programmes. Possible interferences with this development are described in the introduction to Early VoiceGym, which is designed to encourage the shift of the tongue in all children.
Devices that are designed to reposition the tongue without the use of speech or singing are unlikely to succeed long term as the very reason for the tongue shifting to this position was to facilitate speech in Homo sapiens. The larynx must be stabilized before attempting to shift the tongue if it is not to lose its developmental shift downwards. It is not successful to solve one problem by creating another. Neither is it relevant that the lips be sealed in order to breathe through the nose. The seal in Homo sapiens is at the back of the mouth between the tongue 'wedge' and the activated Tensor Palatin to facilitate nose breathing when using the voice, not at the lips.
Successful repositioning decouples the muscle systems of tongue and mandible for nose breathing, swallowing, speech and singing. The tongue becomes the activator in all of these activities. Only in chewing do the muscles of tongue and jaw 'couple', when the mandible becomes the activator.
Using this information:
Dysfunction of the tongue is always accompanied by some developmental impediment. There may be underdevelopment of facial bones, mal-positioning of the mandible or teeth or any combination of these requiring dental, orthopaedic or other structural intervention. A combination of disciplines - a multidisciplinary approach - is increasingly found to be the most successful, both in speed of required result and long term stability.
When changes of this kind are needed in an adult there will be a learned reflex pattern for speech and maybe also singing, that has long established accommodation for a high larynx, forward tongue and many other related interferences that impede the main treatment protocol.
In such a case a change of tongue position requires a whole body exercise programme to adjust head balance, increase pelvic stability and upper body strength. As this inevitably brings dramatic improvement to the voice there is also the consideration of personal and emotional challenge.
Early VoiceGym and VoiceGym are designed to provide a secure and structured pathway to these changes and a way for the patient to take responsibility for them. It is useful to begin VoiceGym, and thus access reprogramming of tongue and face muscles, in advance of dental or structural intervention.
See also chapter 9 of the VoiceGym Book (Jaws and Teeth).