Swallowing involves multiple, highly integrated and partially overlapping actions; however, for discussion purposes, it is frequently separated into three phases— oral, pharyngeal, and esophageal . During the oral phase, food is processed into a swallow-ready ball known as a bolus and is then transported to the back of the mouth. In infants, the oral phase is limited to suction of fluid from a nipple. In children approximately 6 months of age and older, the oral phase may be further partitioned to include the oral preparatory phase, during which solid foods are masticated and prepared for the oral phase. The pharyngeal phase comprises a series of complex and interrelated events that direct and propel boluses through the pharynx into the esophagus while simultaneously protecting the airway. During this phase of swallowing, the velum rises and approximates the pharyngeal walls, breathing stops, the larynx rises, the vocal folds adduct, and the base of the tongue and pharyngeal muscles propel the bolus through a relaxed upper esophageal sphincter. The act of swallowing results in mechanical closure of the airway and cessation of breathing. The esophageal phase begins when the bolus enters the esophagus and ends when it passes into the stomach.

Typical swallowing maturation involves transformation from the primitive sucking and swallowing reflexes used during infancy into the mature and volitional functions of biting, chewing, and bolus formation necessary for the safe and adequate delivery of nutrients in older children and adults. Appropriate adjustments to growth and developmental changes of the aerodigestive system and changes in airway protective responses are essential to competent postnatal maturation processes. Changes in the anatomic relationships of the oral cavity, pharynx, and larynx occur throughout the first few years of life and are well described. In addition, neurodevelopmental, cognitive, and sensory inputs modulate deglutitive function and consequently may influence the maturation process.

Competent deglutition, or swallowing, is crucial to survival. Two primary functions of swallowing are to direct oral secretions, liquids, and food from the mouth to the stomach while protecting the airway and to provide sufficient amounts of nutrients and fluids for children to grow and develop optimally. Appropriate adjustments to growth and increases in nutritional needs are crucial to successful postnatal deglutition. Because breathing and swallowing share common conduits, such as the oral cavity and pharynx, their functions are intertwined.

Dysphagia, or swallowing dysfunction, may be caused by any condition that interferes with the integrity of the structures that comprise the aerodigestive tract or their coordination. Congenital or acquired structural or anatomic anomalies may cause airway and swallowing defects. This chapter focuses on the evaluation of infants and children with suspected dysphagia and the associated primary aerodigestive tract anomalies. Management approaches to swallowing and airway-related problems are reviewed.