Research on Dysphagia Rehabilitation -Relevance of Occlusion for Swallowing-

本研究的目的是开发一种新的系统来评估牙齿因素与吞咽的相关性。在过去的一年中，我们发现咬合支持和舌头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，戴假牙的人很多，因为随着年龄的增长，他们自己的牙齿也会掉光。虽然佩戴和拔除假牙会使口腔发生相当大的变化，特别是在戴全口假牙的人中，但关于吞咽和假牙的研究很少。因此，我们选择戴假牙和拔掉假牙作为评估吞咽的相关性的牙科因素。受试者在不戴上下义齿、不戴上下义齿、不戴上义齿、不戴两副义齿四种情况下，总的吞咽时间和至喉部抬高的潜伏期明显延长。它们的延长是由于预备期和口腔期的延长。尤其是拔除上颌义齿，会扰乱吞咽时舌的稳定运动，影响吞咽的口咽协调，加重随年龄增长的吞咽功能抑制。这些结果表明戴义齿作为牙科吞咽困难康复的一种新方法的重要性。

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.