The rooting reflex is one of the involuntary primitive motor reflexes, which are also known as the frontal release reflexes, that are mediated by the brainstem. It initiates when the corner of an infant’s mouth is stimulated. When the mouth is touched or stroked, the newborn will turn his or her head towards the stimulus and open the mouth with tongue thrusting. The rooting reflex is present at birth (approximately 28 week gestation) and lasts about 4 to 6 months until the frontal lobe of the cerebral cortex develops and suppresses the primitive motor reflexes. As the frontal lobe matures, the primitive reflexes are replaced with voluntary motor functions. The age when each primitive reflex disappears varies. For example, the plantar grasp reflex disappears after about 9 to 12 months.
The rooting reflex is essential for survival and growth as it helps the newborn find the source of food (breast or bottle) and initiate feeding. It is important to differentiate between the rooting reflex and the sucking reflex, which is also involved in nutritional intake. While the rooting reflex occurs when the corner of a baby’s mouth is stimulated, the sucking reflex initiates when the roof of his or her mouth is stimulated. The sucking reflex usually appears around 30 to 35 weeks. The sucking reflex is responsible for the coordination of breathing with swallowing, which starts to develop around 37 weeks. During swallowing, epiglottic closure temporarily interrupts breathing and prevents food from entering the lungs and causing pulmonary aspiration.