||Effect of carbonated water on swallowing performance in healthy volunteers
学位の種類: 博士（歯学）. 報告番号: 甲第4152号. 学位記番号: 新大院博（歯）甲第350号. 学位授与年月日: 平成28年3月23日
We investigated the effect of carbonated water application and swallowing of carbonated water on subsequent swallowing behavior in 12 healthy humans. We performed three experiments, involving 10 min of swallowing carbonated or natural water and 10 min of spitting carbonated water. Before and after each 10-min swallowing or spitting task, we evaluated involuntary and voluntary swallowing behaviors by measuring the onset latency ofthe first swallow after infusing natural water into the pharynx and by counting the number of voluntary swallows for 30 sec, respectively. We found that after 10 min of swallowing carbonated water, the onset latency gradually decreased over a 60-min period. Additionally, the electromyography (EMG) burst duration of suprahyoid muscles significantly decreased after 10 min of swallowing carbonated water. Immediately after 10 min of swallowing natural water, the number of voluntary swallows was significantly smaller compared with the control value. Our results suggest that 10 min of swallowing carbonated water produces a facilitatory effect on the excitability of the brainstem neural network involved in the swallowing reflex. Additionally, the facilitation of this pathway is associated with detrimental changes in swallowing behavior, specifically, shortening of the onset latency of the first involuntary swallow and shortened EMG duration.