Tongue thrust (also called reverse swallow or immature swallow) is the common name of an oral myofunctional disorder, a dysfunctional muscle pattern in which the tongue protrudes anteriorly or laterally during swallowing, during speech, and while the tongue is at rest. Tongue thrust in adults You can carry tongue thrust forward into adulthood from untreated childhood habits or issues. If you're an adult with a tongue-thrusting issue, it could've developed because of chronic allergies or swelling of the adenoids and tonsils. Stress may also be the cause.