BUT, According to Sara Rosenfeld-Johnson, M.S., CCC-SLP these can be PREVENTED and are myths! In her article "The Oral-Motor Myths of Down Syndrome" she explains how.
A basic recap: The tongue shapes the palate. During the closing of the palate, if the tongue is not resting habitually inside the mouth, there is nothing to inhibit plate movement toward midline. The result: myth #1, a high, narrow palatal vault. What is not commonly known is that even children with severe low tone at birth are nose breathers. They maintain their tongues in their mouth and their tongues are not abnormally large. Orally, these children look pretty much like any other infant with the exception that they have a weak suckle. This critical observation draws us to the connection between feeding muscles and muscles of speech.
A cascade of events unfolds for these babies with weak suckle. In this scenario mothers are traditionally encouraged by physicians to use a bottle. Bottle feeding is fine, but the hole in the nipple is often cross-cut or enlarged to make it easier for the infant to suckle. The milk flows easily into the infant's mouth, but what stops the flow, allowing the child to swallow? Tongue protrusion; myth #2. Excessive tongue protrusion is a learned behavior that creates a physical manifestation.
There is a sphincter muscle at the base of the Eustachian tube whose function is to allow air to enter the middle ear. If weak muscle tone reduces the effectiveness of this sphincter muscle, then milk is able to enter the middle ear. The result: chronic otitus media; a primary causative factor in conductive hearing loss; myth #3
Fluid build-up in the middle ear, and the resulting infection, circumfuses throughout mucous membranes of the respiratory system and frequently becomes the originator of chronic upper respiratory infections; myth #4. The nasal cavity becomes blocked, the child transfers from nose breathing to mouth breathing and we have myth #5. The jaw drops to accommodate the mouth breathing, encouraging a chronic open mouth posture; myth #6. Because the tongue is no longer maintained within the closed mouth, the palatal arches have nothing to stop their movement towards midline and we end up with a high, narrow palatal vault, making full circle back to myth #1. The child's tongue remains flaccid in the open mouth posture, at rest. Lack of a properly retracted tongue position is myth #7. This enlarged appearance of the tongue is therefore not genetically coded, but rather the result of a series of care-provider related responses to the very real problem of weak suckle.
Understanding this scenario provides insight into the characteristics seen in these children when speech and language therapists begin to work on correcting their multiple articulation disorders. Addressing the oral muscles/structure from birth offers a more effective, preventative therapy. These physical features are not predetermined.
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