The brain requires oxygen every few seconds and any individual who does not breathe efficiently or whose breathing is limited by a nasal obstruction has a form of UARS. Compromised nasal breathing leads to an increase in mouth breathing and the development of an adaptive tongue/swallow reflex.
The tongue/swallow reflex should be fully developed in utero so the infant can breathe and breastfeed at birth. Until the first teeth appear, nasal breathing and infantile swallow activate the reflexes required for respiration and nutrition. As an infant’s ability to eat solid foods develops, the trigeminal nerve replaces the facial nerve control, theoretically completing the transition from infantile swallow to mature swallow.
Most children today suffer from some form of allergic, inflammatory response to breathing that stresses their sinuses and ultimately hinders the craniofacial growth of their skulls. A strong disruptive factor, second only to malnutrition, is malfunction from altered nasal respiration and posture (Textbook of Craniofacial Growth, Premkumar Sridhar, 2011).
Oral and postural physiology required to maximize the brain’s ability to protect the airway and get oxygen to the brain will affect both swallow and craniofacial growth. Adaptive oral function dictates the skeletal relationship between the mandible and the cranial midface which includes both maxillary bones and both temporal bones. The upper occlusal plane is shaped by the child’s ability to breathe, swallow, and maintain normal head posture. In this clinical example, the mandible shape is ideal. The skeletal asymmetry is found in the midface and multiple bones have been altered in shape, and position to counter the upper airway restriction.