Research on Dysphagia Rehabilitation -Relevance of Occlusion for Swallowing-

本研究的目的是建立一个新的系统来评估牙齿因素与吞咽的相关性。在前一年，我们发现咬合支持和舌运动与吞咽功能密切相关。今年，我们改进了可以同时评估喉部运动的系统。在老年人中，有很多人戴假牙，因为随着年龄的增长，他们自己的牙齿也会脱落。虽然戴义齿和摘义齿对口腔有很大的影响，特别是全口义齿，但关于吞咽和义齿的研究很少。因此，我们选择佩戴和移除义齿作为牙科因素来评估与吞咽的相关性。受试者在四种情况下进行实验：有上下义齿，无下义齿，无上义齿，无两个义齿。总吞咽时间和潜伏期，直到喉抬高显着延长无上下义齿，没有两个义齿。其延长是由于准备阶段和口头阶段的延长。尤其是上半口义齿拔除后，吞咽时舌运动的稳定性受到干扰，影响吞咽的口咽协调性，并随着年龄的增长而加重吞咽功能的下降。这些结果表明，戴义齿作为一种新的方法，从牙科吞咽障碍康复的重要性。

The purpose of this research was to develop the new system that evaluate the relevance of dental factor for swallowing. In the previous year, we found that occlusal support and tongue movement were closely related to swallowing function. This year, we improved the system that could evaluate laryngeal movement simultaneously. In the elderly, there were so many denture-wearers, owing to the loss of their own teeth with aging. Although wearing and removing dentures gave considerable change in their oral cavity, especially, in complete denture-wearers, there was little study about both swallowing and dentures. So we selected wearing and removing dentures as a dental factor to evaluate relevance to swallowing. Subjects were experimented under four conditions ; with upper and lower dentures, without lower denture, without upper denture, without both dentures.Total swallowing duration and the latent period until laryngeal elevation were significantly prolonged without upper or lower denture, and without both dentures. Their prolongation was due to the prolongation of the preparatory and oral stages. Especially, removing upper denture disturbed the stable tongue movement on swallowing, and would affects the oral-pharyngeal coordination of swallowing, and exacerbates the depression of swallowing functions with aging. These results suggested the importance of wearing dentures as a new approach for dysphagia rehabilitation from the dentistry.