At our San Francisco speech therapy practice we get referrals for children, adolescents and young adults with a vague questioning of a tongue thrust or lisp. A tongue thrust (also called a “reverse swallow”) and (“frontal”) lisp can exist separately or together.
The American Speech Language Hearing Association (ASHA) defines a tongue thrust as a tongue moving forward in an exaggerated way during speech and/or swallowing. The tongue may lie too far forward during rest or may protrude between the upper and lower teeth during speech and swallowing, and at rest. A tongue thrust is classified as an orofacial myofunctional disorder (OMD) and in infancy a tongue thrust is normal. However, as children grow they develop a more efficient swallow pattern.
A “lisp” usually refers to a person’s difficulty producing the “s” and “z” sounds because of incorrect tongue placement. The tongue may be sticking out between the front teeth, or the sides of the tongue may not be high enough or tense enough in the mouth. Both of these articulation errors result in sound distortions.
Tongue thrust therapy focuses on training a normal swallow pattern as well as encourage more posterior placement of one’s tongue at rest and while eating. Therapy for a lisp focuses on train correct placement of articulators.
Marshalla, P. (2007). Frontal lisp, lateral lisp. Mill Creek, WA: Marshalla Speech and Language.