Tongue thrust is a common oral habit where the tongue pushes forward against or between the teeth during rest, speech, or swallowing. While it is a normal reflex in very young children, concerns arise when this pattern persists beyond the typical developmental stage. Understanding its natural progression is important for those observing this behavior.
Understanding Tongue Thrust
Infants are born with a natural tongue thrust reflex, also known as the extrusion reflex, which is fundamental for feeding. This reflex causes the tongue to push forward, aiding in nursing or bottle-feeding by preventing choking and facilitating liquid intake. As a child grows, this infantile swallowing pattern transitions to a more mature, adult-like swallow.
The mature swallowing pattern involves the tongue pressing against the roof of the mouth, or palate, rather than pushing against the front teeth. However, in some instances, the tongue continues to push forward against the teeth, which characterizes persistent tongue thrust. This can occur not only during swallowing but also when the mouth is at rest or during speech. The continuous pressure from the tongue against the teeth can influence oral development and function.
Typical Resolution of Tongue Thrust
The infant tongue thrust reflex diminishes as children develop and introduce solid foods into their diet. This transition signals the development of more coordinated oral motor skills necessary for chewing and a mature swallow. For many children, this infantile swallowing pattern naturally resolves without specific intervention.
Natural resolution of tongue thrust typically occurs by ages four to six. As children reach these ages, their oral structures mature, and they develop the muscle coordination required for an adult swallowing pattern. This includes the ability to position the tongue behind the upper front teeth during swallowing, rather than pushing it forward. The self-correction of tongue thrust is a common developmental milestone for most children.
Factors Causing Persistent Tongue Thrust
Several factors can contribute to tongue thrust persisting beyond the typical age of resolution. Prolonged habits such as pacifier use or thumb sucking can reinforce the forward tongue posture, making it difficult for the child to develop a mature swallow. The constant presence of an object in the mouth can train the tongue to rest in a lower and more forward position.
Upper airway obstruction, often caused by chronic nasal congestion, allergies, or enlarged tonsils and adenoids, can also play a role. Difficult nasal breathing leads to mouth breathing, causing the jaw and tongue to drop forward, which can lead to the tongue resting improperly and reinforcing the tongue thrust. Anatomical considerations like a tongue-tie (ankyloglossia) can restrict tongue movement, potentially contributing to an atypical swallowing pattern. Genetic predisposition, such as a family history of similar oral and facial structures, can also increase the likelihood of persistent tongue thrust.
Addressing Lingering Tongue Thrust Issues
When tongue thrust persists into later childhood or adulthood, it can lead to various issues. One common consequence is dental misalignment, such as an open bite where the front upper and lower teeth do not meet when the mouth is closed. The constant pressure from the tongue can also cause teeth to flare out or create gaps between them. These dental problems may require orthodontic intervention.
Persistent tongue thrust can also affect speech, leading to impediments such as a lisp, particularly on “s” and “z” sounds, as the tongue pushes against or between the teeth during sound production. Some individuals might experience difficulties with chewing or swallowing certain foods, or even jaw pain due to misalignment and improper muscle function. Addressing these lingering issues often involves myofunctional therapy, a program to retrain oral muscles and establish proper tongue posture and swallowing patterns. Speech therapy can help correct speech sound errors, and addressing underlying medical causes, such as chronic allergies or enlarged tonsils, can also be part of a comprehensive approach.