The head-rotation maneuver during swallowing has been reported to reduce the occurrence of aspiration in some dysphagic patients. This study examined the effects of head rotation on pharyngeal swallowing in healthy subjects. A helical CT scan was used to study the anatomical change of the pharynx in three volunteers performing the head-rotation maneuver. Further, videofluoroscopic and oropharyngeal manometric examinations of pharyngeal swallowing were performed on seven volunteers with the head in neutral and rotated positions. The helical CT scan revealed that the piriform sinus formed a fusiform shape on the rotated side, and a funnel shape on the opposite side. The videofluoroscopic study revealed that head rotation swallowing lateralizes the bolus away from the rotated head. The pharyngeal manometric study indicated that the pharyngeal peak pressures significantly increased on the side of the head rotated during pharyngeal swallowing. The pharyngeal pressures opposite to the side of the head rotation were not affected but a significant decrease in the upper esophageal sphincter (UES) resting pressure was noted. We concluded that head rotation swallowing in normal subjects not only alters the bolus pathway but also increases the function of pharyngeal clearance, and therefore UES dynamics.
