Q: I have heard you say that if kids have problems with sibilants and are missing their front teeth you prefer not to see them until their teeth come in. Could you explain your rationale?

Without front teeth true stridency cannot be produced. Stridency is produced as the midline air stream hits the front teeth and then escapes between them.

Without front teeth, a client would have to be taught a compensatory movement. He would have to produce his sibilants with the tongue-tip directing the air stream to the side teeth resulting in a lateral lisp. Or he would have to lift the tongue tip up and direct the air stream against the alveolar ridge. A fricated sound would result, but it would be a slightly distorted – broad and somewhat sloppy sound that is lacking in true stridency.

All children go through a period when the deciduous teeth fall out as the permanent teeth begin to poke through. We should wait to fix a frontal or lateral lisp until after this process has been complete. This is not a new idea. Older textbooks on articulation therapy discussed this. It was usually recommended that we wait to treat a frontal or lateral lisp until a child has gained his permanent teeth. The waiting period may only be a few weeks or months. Thus we can work on tongue placement for sibilant production in the average client either before or after the baby teeth fall out. The client should take a break while the front teeth, especially the top front teeth, are missing.

We must distinguish between helping a child gain stridency and helping a child fix a frontal or lateral lisp. We can stimulate for frication or stridency in very young children. One- and two-year-olds use the strident phonemes all the time with great success. However, we cannot expect a child to produce refined sibilant phonemes unless his baby or adult teeth are in place. Optimum mature articulation of the sibilants cannot be produced while the front teeth are missing.

A client who has front teeth that are permanently missing has to be taught to compensate for this particular structural problem. He has to be taught to produce his sibilants with the tip high so the air stream can strike the alveolar ridge, or he has to be taught a lateral lisp. In the ideal case, the client’s anterior teeth would be replaced with implanted false teeth.

In Oral-motor Techniques in Articulation and Phonological Therapy, I discuss a “Hierarchy of Thinking” I use when it comes to treating speech production problems. I explain that we “fix the structural, habitual and medical fixables” before we tackle the articulation problem. Missing teeth would fall into the category of a structural problem that can be fixed, either through waiting for natural change or by initiating dental or orthodontic procedures.