The tongue thrust reflex, also known as the extrusion reflex, is an involuntary movement observed in infants from birth. It involves the tongue pushing forward when something touches or comes near a baby’s lips. This reflex is a normal part of early development, serving purposes in feeding and protection.
How the Tongue Thrust Reflex Appears
The tongue thrust reflex is observable during feeding or when an object approaches an infant’s mouth. When a spoon or solid food touches the baby’s tongue or lips, the tongue involuntarily pushes forward, often protruding past the lips. This action often expels food from the mouth, making feeding attempts messy.
The lips might remain slightly open or struggle to form a tight seal around a spoon, contributing to the expulsion of food or liquid. This forward movement of the tongue prevents the infant from effectively drawing food from the front of the mouth to the back for swallowing. Consequently, the baby may appear to reject food, not from dislike, but because the reflex pushes it out.
The Reflex’s Natural Progression
The tongue thrust reflex serves a protective function for infants, helping to prevent choking by ensuring only liquids are easily swallowed in the early months. This reflex also facilitates successful latching during breastfeeding or bottle feeding, guiding milk towards the back of the mouth for efficient intake. Babies’ oral muscles are not yet developed enough to swallow anything other than fluids, making this reflex necessary for early nourishment.
The reflex typically diminishes as an infant develops oral motor skills, usually between 4 and 6 months of age. This integration signals the baby is developing coordination to move solid food from the front to the back for swallowing. The disappearance of the tongue thrust reflex is a normal developmental milestone, indicating readiness for the introduction of solid foods.
When Tongue Thrust Persists
If the tongue thrust reflex continues beyond the typical developmental age (generally 6 to 12 months), it indicates persistent tongue thrust. Signs include prolonged tongue pushing during feeding or at other times. Babies might also show difficulty latching onto the breast or bottle, leading to inefficient feeding.
Other indicators include exaggerated forward tongue movement during swallowing, often resulting in messy eating. Older children might display an open-mouth posture or breathe predominantly through their mouth. Persistent tongue thrust can also contribute to speech sound difficulties, such as a lisp (where “s” sounds might be pronounced like “th”) or issues with “t,” “d,” “n,” “l,” and “sh” sounds. It can also lead to dental problems like an open bite (where upper and lower teeth do not meet) or misaligned teeth due to continuous tongue pressure. If these signs are noticed, consult a healthcare professional like a pediatrician or dentist.