Physiology of oral swallowing studied by ultrasonography. 
The aim of the study was to identify a number of sonographic landmarks in the evaluation of the oral phase of swallowing.  Forty non-dysphagic adults (average age 38 years) and 20 normal bottle-fed newborns (average age 13 days) were submitted to videorecorded sonographic examination using two types of transducers (5 and 7.5 MHz).  The adults were asked to swallow a 20 ml bolus of water and the newborns were examined while sucking from a bottle containing milk.  Preliminary transverse scans of the neck were obtained to evaluate laryngeal movements during swallowing.  The mouth was examined through the submental window using sagittal and coronal scans.  In the newborn, additional transbuccal scans were employed.  In both adults and newborns highly significant and reproducible images of single-element motor events involved in swallowing were obtained.  Normal sonographic images of the oral stage of deglutition form the baseline from which abnormal patterns may then be recognized.