The major focus of this year's research has been to develop a set of baseline data on hyoid motion during the oral phase of swallow on normal adults across age groups to use in future studies of disordered populations. The effects of ageing (Sonies, et al) and Xerostomia (Fox, et al) on swallow are under study. We have completed studies on 49 normal adult ages 18 to 79 and 30 Xerostomics. Normal ranges of hyoid motion have been established for distance and duration of movement. Effects of order and time on tongue movement patterns are being studied. Dry and wet swallows with 1 oz. and 10 cc of water are compared. Duration and distance are now measured using both 5 and 3.5 MHz transducers positioned submentally scanning both anteriorly and posteriorly. Various materials (steel and plastic) were scanned using a water bath phantom to determine whether they could serve as a reference marker when scanning the oral cavity (Shawker, et al). A """"""""comet-tail"""""""" reverbation artifact was visible using stainless steel pellets placed at the phantoms water-air interface and at the tongue surface-air interface in a normal subject. This discovery solves a previous research problem of locating a permanent reference point on a moving surface. Using the reverberation artifact as a reference, the excursions of pellets on the tongue and floor of the mouth were able to be tracted. Simultaneous real time display of changes in tongue surface configuration and internal musculature can now be studied in vivo during speech and swallowing. These advances should prove useful by: (a) providing a new noninvasive method to diagnose disorders in the oral phase of swallow which were previously unobservable; (b) providing data across the life span for studies of aging and swallowing; (c) providing normal ranges for comparison with disordered swallowing populations; (d) alleviating the problem of location of a stable reference point on the tongue for speech science research with ultrasound; (e) stimulate other researches in the field.
