Tongue thrusting, also known as an orofacial myofunctional disorder, describes a pattern where the tongue pushes forward against or between the teeth during swallowing, speaking, or when resting. For a newborn, a tongue thrust is a normal, protective reflex, often called the “extrusion reflex.” This reflex facilitates nursing and prevents choking by creating a seal while the infant suckles. The behavior typically begins to disappear around six months of age as the baby prepares for solid foods. Its persistence into later childhood, however, becomes problematic.
The Mechanics of Tongue Thrusting Versus Normal Swallowing
The swallowing process in infants, referred to as the infantile or visceral swallow, fundamentally differs from the mature pattern. During infantile swallowing, the tongue positions itself between the gum pads. Its tip presses forward against the lower lip to stabilize the lower jaw, and active contractions of the lip and cheek muscles create the necessary suction for feeding.
The transition to a mature, or somatic, swallow should begin as the child introduces solids, typically between six and twelve months of age, and is usually established by age four or five. In a mature swallow, the tongue tip elevates and presses against the hard palate, just behind the front teeth. This upward and backward movement eliminates undue pressure on the teeth and utilizes the stronger back muscles of the tongue and throat. Tongue thrusting occurs when the forward movement of the tongue tip persists, failing to transition to the mature, palatal-based pattern.
Identifying Underlying Causes and Risk Factors
The failure to transition from an infantile swallow is often linked to a combination of anatomical, respiratory, and habitual factors. A primary contributor is chronic nasal obstruction, caused by conditions like allergies or enlarged tonsils and adenoids. When a child cannot breathe easily through their nose, they become a mouth breather. This forces the lower jaw and tongue forward and down to maintain an open airway.
Habitual factors also play a large role, including the prolonged use of pacifiers, sippy cups, or bottle nipples past the age of three. These items automatically position the tongue low and forward, reinforcing the immature swallowing pattern. Furthermore, a physical restriction such as a tongue tie (ankyloglossia), which limits the tongue’s mobility, can encourage a forward thrusting motion as the baby attempts to compensate. Genetic predisposition can also be a factor, as inherited hyperactivity of the mouth muscles may increase the tendency to develop the habit.
Observable Signs and Impacts on Development
Parents can observe several signs that may indicate a persistent tongue thrusting habit in their child. During swallowing, the tongue may be visibly pushing forward against or protruding between the front teeth. This forward pressure can make eating messy, as food or liquid may escape the mouth easily, and it can also lead to difficulty with chewing.
When the child is at rest, observable signs include an open-mouth posture and an inability to seal the lips fully, which often accompanies mouth breathing. Over time, the repeated pressure of the tongue against the teeth—which can be up to four pounds with each swallow—begins to affect dental alignment. The most common resulting issue is an anterior open bite, where the upper and lower front teeth fail to meet when the mouth is closed. The abnormal tongue position can also impact articulation, frequently causing a lisp on sounds like “s” and “z”.
Professional Assessment and Treatment Options
Addressing a persistent tongue thrust requires a multidisciplinary approach involving specialized professionals. A pediatric dentist or orthodontist assesses the effect of the thrust on tooth alignment. A speech-language pathologist (SLP) or certified orofacial myologist evaluates the muscular patterns of the mouth and face. The assessment process includes observing the child’s tongue posture at rest, during speech, and during swallowing.
The primary corrective approach is Orfocial Myofunctional Therapy (OMT), which involves targeted exercises to retrain the oral and facial muscles. These exercises teach the tongue the correct resting position on the palate and establish a mature swallowing pattern. If the thrust has already caused dental issues, an orthodontist may recommend appliances like a tongue crib or habit breaker, which acts as a physical barrier to discourage forward movement. For underlying structural problems, such as a severe tongue tie, a minor surgical procedure like a frenectomy may be necessary to restore full tongue mobility before OMT can be fully effective.