Extrusion reflex, also known as tongue thrust reflex, is one of the many newborn reflexes. In this reflex, an infant opens the mouth and extends the tongue when their lips are touched (1). The extrusion reflex serves a purpose and is a sign of an infant’s normal development.
The reflex fades away as the baby grows older, and its persistence beyond infancy may indicate an underlying orthodontic problem. This post tells you about extrusion reflex in babies, the time of its disappearance, and signs that indicate extrusion reflex could be a problem.
Why Do Babies Have Extrusion Reflex?
The newborn reflexes are spontaneous, involuntary actions that are a part of a baby’s normal development. Some of these reflexes occur during a specific developmental stage and then diminish as the baby grows. The presence of these reflexes helps determine if the baby’s brain and nervous system are working fine.
The extrusion reflex is one of the newborn reflexes. It causes a baby to extend out their tongue in response to their lips being touched. It does not interfere with the baby’s ability to latch onto a breast or bottle nipple but prevents them from feeding from a cup or a spoon. Along with the gag reflex, it lets the baby expel any solid food if they are not ready for it (2). Thus, the extrusion reflex protects the baby from choking or aspiration due to solid foods and other foreign objects.
When Does Extrusion Reflex Develop?
The extrusion reflex is present at birth, indicating that the baby develops it during fetal life. It is not precisely known when the fetus develops this reflex. It may develop between 32 and 36 weeks of gestation when other newborn reflexes, such as the sucking reflex, also develop (3)
When Does Extrusion Reflex Disappear?
The extrusion reflex disappears between the ages of four and six months (4). It is the age range when babies are ready for solids and can sit without support (5). Since the baby is ready to transition to solid food, the extrusion reflex is no longer needed.
There are other signs that accompany the fading extrusion reflex and indicate the baby’s readiness for solids. According to the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP), an infant is ready to transition to solids when they display the following attributes (6) (7).
- Ability to sit in a high chair or feeding table without support and with good head control
- Opens mouth when the food is offered, or a spoon approaches them
- Swallows food and does not push it out of the mouth
- Ability to transfer the food from the front to the back of the tongue
- Doubles their birth weight
If you are unsure if the baby still has their extrusion reflex, you may test to check its presence.
How To Test If Baby’s Extrusion Reflex Persists?
Parents can check for extrusion reflex by offering a clean spoon to the baby. If the baby thrusts their tongue and pushes the spoon, then they still have the extrusion reflex. If the baby accepts the spoon, the extrusion reflex is gone.
Babies older than six months seldom have tongue thrust, and parents can begin offering them solids. However, some babies may continue to have extrusion reflex despite being ready for solids. You may have to see a healthcare provider in such cases.
When To See A Doctor?
Consult a pediatrician if your baby has extrusion reflux beyond the age of six months. A baby with persistent extrusion reflex may also display the following signs (8).
- Too fast, too slow, or messy eating with constant dribbling of food
- Unable to close the lips completely
- Tongue sticks out when the mouth is at rest or when the baby eats or talks
- Problem chewing solid food
- Speech problems in case of older babies
Persistent tongue thrusting in babies could indicate an orofacial myofunctional disorder, which may lead to orthodontic problems, such as misaligned permanent teeth, later in life (9). It may also affect the baby’s speech development.
A pediatrician or an orthodontic specialist will suggest the appropriate treatment plan to treat the underlying problem, such as orofacial muscular problems, and cure extrusion reflex.
What Other Reflexes Do Babies Have?
- Sucking reflex: If a breast or bottle nipple is placed on the baby’s lips, they automatically begin to suck. The reflex usually wanes by four months of age.Premature babies may have an underdeveloped sucking reflex.
- Rooting reflex: If the corners of the baby’s mouth, cheeks, or lips are touched, the baby turns in the direction of touch and opens their mouth. Rooting reflex helps babies locate the breast or bottle nipple and begin feeding. The reflex tends to fade away by four months of age.
- Gag reflex: The infant gags and pushes out a piece of food or object present at the back of the mouth. The gag reflex lets the baby propel food or any other foreign object towards the tongue and then out of the mouth. It reduces the risk of choking. The gag reflex fades away by four to six months of age. Adults retain the reflex to some extent.
- Moro or startle reflex: Moro reflex occurs when the baby is startled by a loud noise or movement. The startled baby may cry, throw their head back, extend their arms and legs out, and then pull them back. The reflex serves the purpose of garnering a caretaker’s attention. The reflex diminishes by two months of age.
- Tonic neck reflex: If the baby’s head is turned to one side, their arm on that side straightens, and their opposite arm bends. It is also called the fencing position, and the reflex wanes by five and seven months.
- Grasp reflex: If you touch or stroke your newborn’s palm, they grasp your finger or the object by closing their fingers in a grasp. It is also called palmar grasp reflex and diminishes between five and six months of age.
- Babinski reflex: It is also known as plantar grasp reflex. If you stroke the sole of the baby’s foot, they respond by moving their big toe upwards while spreading out their remaining toes. This reflex usually fades away by two years of age.
- Stepping reflex: If the baby is held upright with their feet in contact with a surface, they begin to move their legs in a stepping action, as if climbing a flight of stairs. This reflex wanes by two months of age.
Extrusion reflex is one of the essential newborn reflexes, and it prevents aspiration or choking in babies. This reflex gradually fades by the time the baby is ready for solids, which is around the age of six months. If the reflex persists beyond six months, speak to a doctor for evaluation and treatment.