Tongue thrust and frontal lisp are commonly confused, as both result in a ‘th’ when attempting to produce the ‘s’ and ‘z’ phonemes. The frontal lisp is classified as an articulatory error, as the tongue is simply being placed incorrectly between the upper and lower front teeth during sound production. When an individual has a tongue thrust, the tongue’s position sits forward in the mouth at all times, even when swallowing and at rest. All sounds can be affected by this forward-sitting position, especially the ‘s’ and ‘z’ phoneme.
Tongue thrust is the most common Orofacial Myofunctional Disorder (OMD). Orofacial Myofunctional Disorders are anatomical and physiological differences of oral and facial structures (lips, teeth, tongue, jaw, cheeks, and palate) that are noticeably different; interfere with normal dentofacial, speech, physical or psychosocial development; or that are of cosmetic concern. These include lip and tongue rest, swallow, and speech posture differences. (Hale, Kellum, & Gross 1991). Granite Bay Speech provides a free phone consultation to answer your questions about any speech-related disorder.