Development of Oral Habits and Maturation of Oral Functions

Abstract

At birth the neonate’s survival depends on instinctive sucking when lips and tongue are stimulated. Soon after, the mouth is used as the primary device for exploring the environment. When an object is placed in a baby’s hands or within his/her reach, the first thing the baby does is to put the item into his/her mouth, almost as if it is using the mouth to see this new environment. At the beginning the infant makes an effort by frequent learning and practice, later on the muscles start responding more readily. At the outset it takes a long time for the impulses to pass along the afferent nerves to the brain and back along the efferent nerves to the muscles involved. It has been stated that unconscious mental pattern of childhood develops from five sources, namely, instinct, insufficient or incorrect outlet to energy, pain or discomfort, abnormal physical size of parts, imitation of or imposition of others. The important physiologic functions of the oral cavity are respiration, swallowing, mastication and speech. Infants are obligatory nasal breathers but the mandible and tongue must be positioned away from the posterior pharyngeal wall for the airway to be patent. If nasal breathing becomes obstructed, oral breathing must commence. Therefore, respiratory needs are the primary determinant of mandibular posture and tongue position. As the child grows and motor skills develop, there is improved motor control of the tongue and oral musculature. There appears to be a gradient of oral function maturation from anterior to posterior. In addition, the infant develops the ability to control a bolus with lateral and anteroposterior movements. This improved oral motor control helps the child to handle changes in the consistency of their diet and enables them to control a bolus of food with increased skill.