ppropriate nutritional intake is essential for the rapid growth and development that occurs during infancy and childhood. 1 Feeding and swallowing dysfunction are diagnosed with increasing frequency, especially in children with a history of prematurity, neuromuscular disorders, cardiopulmonary disorders, anatomic anomalies of the upper aerodigestive tract, and gastrointestinal tract disorders. [2][3][4] Early diagnosis and intervention by a multidisciplinary team are essential to the management of swallowing disorders in children. 5
Physiologic Characteristics of SwallowingThe normal swallow is classically divided into 4 phases: the preparatory phase, the oral phase, the pharyngeal phase, and the esophageal phase. The preparatory phase is when food is taken into the oral cavity, moistened with saliva, chewed, and prepared into a bolus using the oral tongue and hard palate. This phase develops at approximately age 6 months. Before age 6 months, the preparatory phase consists of sucking from a nipple. The oral phase is the propulsion of the food bolus into the oropharynx by the oral tongue and the triggering of the swallow reflex. The soft palate elevates to prevent food from regurgitating into the nasopharynx. The pharyngeal phase is the passage of the food bolus through the oropharynx and hypopharynx toward the esophagus via coordinated muscle contraction. The velum approximates the pharyngeal musculature, the larynx elevates and the vocal folds adduct, and the tongue and pharyngeal muscles propel the bolus into the pharynx. 2,5,6 Respiration ceases during the pharyngeal phase; in fact, while eating, the respiratory rate becomes faster and more irregular than during tidal breathing. 7,8 The esophageal phase consists of cricopharyngeus relaxation, allowing the food bolus to enter the esophagus, and coordinated smooth muscle peristalsis passes the bolus into the stomach. 2,9 Development of the suck and swallow begins in utero as early as gestational week 10 or 11. Gestational age 34 to 38 weeks is typically when most children develop efficiency and tolerance of oral feeding. 5,10,11 In infants, all 4 phases are under involuntary reflex control. In children and adults, the preparatory and oral phases are under voluntary control, and the pharyngeal and esophageal phases remain involuntary. 2 A physiologic swallow is the result of the complex integration of more than 30 nerves and muscles and must progress with the child as their anatomy matures. 2 Dysphagia is defined as difficulty swallowing and must be distinguished from behavioral feeding disorders, such as oral aversion. 1 Dysphagia can be further categorized depending on the disordered phase of swallowing. Oral dysphagia can present as absent oral reflexes, immature or absent suck, uncoordinated biting/chewing, and poor handling of the food bolus. Pharyngeal dysphagia can present as laryngeal penetration, when the food bolus enters the laryngeal vestibule; aspiration, when the food enters the airway below the vocal folds; choking, when food obstructs the airway...