Q: I have a 3-year-old whose front teeth had to be pulled due to decay. He likely won’t have those teeth again for 2-4 years. Do I wait to treat S?

This depends upon what you are trying to accomplish…

First, if you are trying to bring stridency into the client’s phonological system, and are stimulating S to do that, I would do it now.  In fact, I would stimulate for all the strident phonemes right away –– S, Z, Sh, Zh, CH, J.  In this case, you are not trying to teach the phonemes. Instead you are trying to introduce stridency into his phonological system.  It will not matter which phoneme is gained first, second, and so forth.  And it will not matter if any of these phonemes are produced perfectly.

Second, he will not be able to produce a perfect S without any front teeth, so he will have to learn to compensate for the structural problem.  This is a basic Van Riper concept.

The compensation that is used until the new teeth arrive could be one of several, and depends upon what you think sounds best and what you observe that he can handle:

• He could learn to produce his S laterally, so the sound comes out the side where presumably he has some teeth.
• He could make a fricated sound by placing the tongue-tip right next to the alveolar ridge.  The tinier he makes the opening between the tongue-tip and the ridge, the more fricated it will sound.
• He could produce the sibilants with the tongue between the lips so that frication is formed between the tongue-tip and the upper lip.
• Or you could teach him a phoneme substitution that will serve as a placeholder for S until his teeth arrive.  He could use t/s and d/z.