A tongue thrust is an abnormal movement of the tongue during swallowing and/or speech. Instead of moving up and back as it should during a swallow, the tongue pushes down and forward against or between the front teeth. Although a “tongue thrust” swallow is normal in infancy, it usually decreases and disappears as a child grows. If the tongue thrust continues, a child may look, speak, and swallow differently than other children of the same age. Both dentists and orthodontists may be involved when constant, continued tongue pressure against the teeth interferes with normal tooth eruption and alignment of the teeth and jaws. Some children produce sounds such as /s/, /z/, /sh/, /zh/, and /ch/ incorrectly as a result of a tongue thrust. Also, the sounds /t/, /d/, /n/ and /l/ may be produced incorrectly because of weak tongue tip muscles. Sometimes speech may not be affected at all.