[Effects of tongue pressure sensor sheet on the signal waveform of laryngeal movement produced by bend sensor during deglutition].

OBJECTIVE: To evaluate the effects of the application of tongue pressure sensor sheet on the signal waveform of laryngeal movement produced by the bend sensor during deglutition. METHODS: Twelve adult male subjects were recruited to perform a single swallow of 5 ml water when sitting on the dental chair with upright position. The data recorded by bend sensor was obtained with attaching tongue pressure sensor sheet simultaneously or not. Then the measured parameters by bend sensor with or without concurrent application of tongue pressure sensor sheet were compared. RESULTS: There were no significant differences between the same time point on the signal waveform produced by bend sensor whether concurrently attaching tongue pressure sensor sheet or not (P > 0.05). Additionally, we found no statistical significances between matched phases on the signal waveform recorded by bend sensor with or without application of tongue pressure sensor sheet (P > 0.05). CONCLUSION: The findings in this study suggest us that the usage of tongue pressure sensor sheet exerted no influences on the waveform of the laryngeal movement produced by bend sensor during deglutition, facilitating us to further apply tongue pressure sensor sheet and bend sensor simultaneously to record tongue pressure production and hyoid activity during deglutition.

Tongue pressure generation during tongue-hold swallows in young healthy adults measured with different tongue positions.

Tongue-hold swallow (THS) has the potential to be a resistance exercise not only for the pharyngeal constrictor but for the tongue muscles. To elucidate the physiological mechanisms of THS, this study investigated intraoral pressure generation during THS in relation to different extents of tongue protrusion. Tongue pressure was measured by a 5-point pressure sensor sheet placed onto the hard palate of 18 healthy young subjects who performed three swallow tasks: normal dry swallow, THS with slight tongue protrusion, and THS with greater tongue protrusion. Subjects randomly repeated each task five times. Maximum range of tongue protrusion was also measured in each subject to estimate lingual flexibility. With an increase in the extent of tongue protrusion, pressure generation patterns became irregular and variable. Duration of pressure generation increased with statistical significance in the posterior circumferential parts of the hard palate (p < 0.05). Maximal magnitude and integrated value of the pressure recorded at these locations increased in eight subjects as the extent of tongue protrusion increased, but it decreased in nine. The former group showed greater lingual flexibility, while the latter group exhibited less flexibility. THS may place different amounts of load on the tongue muscles by adjusting the degree of tongue protrusion.

Development of a system to monitor laryngeal movement during swallowing using a bend sensor.

BACKGROUND: Swallowing dysfunction (also known as dysphagia), which results in a deterioration of nutritional intake, slows rehabilitation and causes aspiration pneumonia, is very common following neurological impairments. Although videofluorographic (VF) examination is widely used for detecting aspiration, an objective and non-invasive method for assessing swallowing function has yet to be established because of a lack of adequate devices and protocols. In this paper, a bend sensor whose resistance is altered by bending was introduced to monitor swallowing-related laryngeal movement. METHODS: Six healthy male volunteers were recruited in the present study. Specific time points on the signal waveform produced by the bend sensor were defined to describe laryngeal movement by differential analysis. Additionally, the physiological significance of the obtained waveform was confirmed by analyzing the sequential correlations between the signal waveform from the bend sensor and hyoid bone kinetics simultaneously recorded by VF. RESULTS: Seven time points were successfully defined on the signal waveform to reference laryngeal movement. Each time point was well correlated with certain VF events, with evidence of no significant time lags, and there were positive correlations between waveform time points and matched VF events. Furthermore, obvious similarities were noticed between the duration of each phase on the signal waveform and the duration of the matched hyoid bone activity. CONCLUSIONS: The present monitoring system using a bend sensor might be useful for observing the temporal aspects of laryngeal movement during swallowing, and it was well coordinated with hyoid bone movement.

Movement of the mandibular condyle and articular disc on placement of an occlusal splint.

OBJECTIVE: The aim of this study was to evaluate, with the use of magnetic resonance images, mandibular condyle and articular disc movement on occlusal splint application. STUDY DESIGN: Thirty-five subjects were classified into "Pain" and "No-pain" groups based on visual analog scale scoring of temporomandibular joint (TMJ) pain and were categorized as bilateral normal disc (ND), unilateral anterior disc displacement (ADD), or bilateral ADD position. t test and analysis of variance with multiple comparisons were used for statistical analyses. RESULTS: Pain and No-pain groups showed significant anteroinferior and rotated movement of the condyle on splint application, but the disc did not significantly move in the Pain group. Of all groups, anteroposterior movement of the condyle and disc with the splint was significantly less in the unilateral ADD group. CONCLUSIONS: TMJ pain was associated with decreased movement of the articular disc. Disc and condyle movement was different in the unilateral ADD group in the presence of a splint compared with the ND and bilateral ADD groups.