A lisp is a relatively common speech disorder in which a person has trouble pronouncing the sounds of the letters “s” and “z.” The toddler that says “pleathe” is really cute, but how do you decide when the lisp is no longer cute?
And why on earth does the word “lisp” contain an /s/? 😛
There are a number of factors to consider:
Type of lisp
- Interdental/frontal lisp: The tongue protrudes out through the teeth and the /s/ and /z/ sounds will then sound more like a “th” sound
- Dentalized lisp: This is when the /s/ and /z/ sounds are produced with the tongue actually touching or pushing up against the front teeth.
It is a perfectly normal developmental phase for some (but not all) children to lisp until they are about 4½ years old.
However the following types of lisps are usually NOT developmental and will usually require intervention
- Lateral lisp: This lisp is often referred to as “slushy.” A lateral lisp occurs when the tongue tip is in a similar position to make the /l/ sound, but the air flow, instead of being directed forward and out of the oral cavity, escapes out and over the sides of the tongue.
- Palatal lisp: A palatal lisp results when “the mid section of the tongue comes in contact with the soft palate, quite far back. If you try to produce…an “h” closely followed by a “y” and prolong it, you more or less have the sound” (Caroline Bowen)
A tongue thrust is likely to result in an interdental or dentalised lisp that does not self correct.
What is a tongue Thrust?
All babies have a tongue thrust or reverse swallow. When the baby swallows, his tongue pushes forward toward his gums or front teeth. For example when feeding a baby pureed food. The baby’s tongue pushes forward, pushing some of the food back out of his mouth. The adult scoops the food off his lips and face with the spoon and puts it back in his mouth and the cycle continues. As babies mature, they learn, not only to keep their lips closed when they swallow, but to effectively move the food back toward the throat with a more mature swallow.
In the mature swallow, the tongue tip is held on the alveolar (gum) ridge behind the top front teeth and the tongue efficiently moves the food backward with a rolling motion.
Children should have a normal, adult swallow by the time they are 7 years old.
What causes Tongue Thrust?
- Thumb sucking and/or nail biting
- Prolonged use of a dummy
- Prolonged use of Sippy Cups
- Mouth breathing
- Premature loss of “baby” teeth
- Lack of muscle coordination
- Hereditary factors
- Enlarged tonsils & adenoids
What are some signs of having a tongue thrust problem?
One or more of the following conditions may indicate that there is a tongue thrust and should be further investigated by a speech therapist.
- Tongue protruding between or against the upper and/or lower “front teeth” when forming /s/, /z/, /t/, /d/, /n/. The /j/, /ch/ and /sh/ sounds may also be affected.
- Response to traditional speech therapy poor.
- Frequent open-mouth resting posture with the lips parted and/or the tongue resting against the upper and/or lower teeth
- Protrusion and/or “splaying” of front teeth.
- Lips that is often cracked, chapped, and sore from frequent licking
- Frequent mouth breathing in the absence of allergies or nasal congestion
Treatment of a tongue thrust requires breaking a habit that has been ingrained! It requires dedication and practice. For this reason, I would advise waiting until the child is around 7 years old.
Remediation of a functional articulation error of the /s/ and /z/ sound can be done at an earlier age.