Tongue thrust is an atypical swallowing pattern where the tongue presses forward against or between the teeth. This is common in infants as a natural feeding reflex, usually resolving by four to six months as solid foods are introduced. If it persists, it can become an oral myofunctional disorder, continuing into childhood and sometimes adulthood. It can lead to various oral health and speech concerns.
Visual Cues of Tongue Thrust
Initial indications of tongue thrust are visible in the resting position of the tongue and mouth. Individuals often exhibit a low tongue posture, resting against the teeth or on the floor of the mouth instead of the roof. This contributes to an open-mouth posture, with parted lips and potential mouth breathing. The tongue may also visibly protrude between the front teeth at rest.
The tongue may also push forward against or between teeth during speech or swallowing. This is noticeable with front teeth, where constant pressure can create indentations or spaces. The lower lip might pull tightly when swallowing, and chin muscles may appear strained or dimpled.
Functional Indicators During Swallowing and Speech
Tongue thrust also manifests through actions and sounds during eating and speaking. When swallowing, the tongue pushes forward against the teeth or between the dental arches instead of pressing against the roof of the mouth. This atypical motion can be observed as a visible effort or strain around the mouth during swallowing. Difficulty keeping food in the mouth or messy eating habits may also occur, as the tongue does not effectively manage food.
Speech difficulties are another functional indicator. The forward tongue position can lead to a lisp, particularly affecting “s” and “z” sounds, making them sound like “th.” The tongue may protrude between teeth when producing these sounds, or airflow might escape from the sides, creating a “slushy” sound. Other sounds like “sh,” “ch,” “j,” “t,” “d,” “n,” and “l” can also be impacted.
Dental and Facial Development Alterations
Persistent tongue thrust exerts significant pressure on teeth and jaw, leading to noticeable changes in dental alignment and facial structure. The constant forward force can push teeth out of their natural position. A common result is an anterior open bite, where upper and lower front teeth do not meet when the mouth is closed, leaving a visible gap.
The tongue’s pressure can also cause upper front teeth to protrude outwards, known as overjet. Lower front teeth might also tilt inwards due to the tongue’s pressure. Gaps can also form between teeth, most commonly between the two upper front teeth. Continuous muscle imbalance and altered resting posture can also influence facial muscle development, potentially contributing to an elongated facial appearance.
When to Consult a Professional
If persistent signs of tongue thrust are noticed, especially in a child over four, professional evaluation is advisable. A dentist or orthodontist can assess dental misalignments, such as an open bite or protruding teeth, linked to tongue thrust. They can also determine jaw development impact.
A speech-language pathologist or myofunctional therapist can evaluate swallowing patterns, speech difficulties, and oral muscle function. Early intervention is beneficial, particularly if tongue thrust affects speech, eating, or dental development. These professionals provide a comprehensive diagnosis and guide further steps.