Abstract
Objective: The purpose of this study was to clarify whether a carnival blower is useful for evaluating velopharyngeal function.
Method: Two groups of carnival blowers were used in this study. Each group was comprised of ten carnival blowers provided by two manufacturers (O and Y) . Experiments in this study were performed under two conditions: I) when the carnival blower is changed from a rolled-up position to the condition of being completely extended; II) when the blower is maintained in a rolled-up position. Extension of the carnival blowers and maintenance in the extended position were performed by means of regulation of airflow volume using a machine blower connected to the carnival blower. Air pressure in each condition was measured through a catheter inserted into the cavity of the system.
Results: Under condition I, the average value of air pressure was identified to be 33.2 (SD 3.4, CV 0.10) and 40.5 (SD 4.0, CV 0.10) cmH2O for blowers by O and Y manufacturers, respectively. Under condition II, the average value of air pressure was identified to be 1.7 (SD 0.8, CV 0.48) and 3.1 (SD 0.3, CV 0.10) cmH2O for blowers by O and Y manufacturers, respectively. Under both conditions, greater air pressure was measured for carnival blowers made by manufacturer Y. Moreover, with both types of carnival blower, air pressure was greater under condition I than under condition II (student t test: p<0.01) . This variation was observed not only between the carnival blowers of the two manufacturers, but also within the carnival blowers of the same manufacturer.
Conclusion: This study clarified that during blowing of a carnival blower, oral air pressure may range variously in relation to differences in the condition of the rolled paper. These findings indicated that evaluation of velopharyngeal function using carnival blowers may be inconsistent.
