Division of Removable Prosthodontics, Department of Prosthodontics, School of Dentistry, Iwate Medical University, Iwate, Japan.
J Oral Rehabil. 2012 Apr;39(4):277-84. doi: 10.1111/j.1365-2842.2011.02263.x. Epub 2011 Oct 15.
Dysphagia rehabilitation in the elderly includes direct therapy to alter the three-dimensional shape of the oropharynx so that food boluses can pass safely through the poorly functioning pharynx. Alteration of the mandibular position is thought to affect oropharyngeal shape, but this relationship remains poorly understood. We therefore studied the relationship between mandibular position and three-dimensional shape of the oropharynx in the seated posture normal for feeding. Ten healthy, dentate subjects participated (average age, 28·1 years). Experimental mandibular positions were the intercuspal position, bite-raised position and mandible-advanced position. The oropharynx was scanned in a 90° seated posture using dental cone-beam computed tomography, and the effects of changes in mandibular position were analysed after obtaining oropharyngeal volume, height, sectional area, average sectional area of oropharynx and the position of the epiglottis. Oropharyngeal volume and average sectional area increased significantly in the mandible-advanced position compared with other mandibular positions. Notably, the volume and average sectional area of the inferior part of the oropharynx increased significantly. Oropharyngeal height and sectional area at the base of the epiglottis showed no significant difference in bite-raised position and mandible-advanced position compared with intercuspal position. The position of the epiglottis moved significantly forward in the mandible-advanced position. The results of this study show that in a seated posture, volume of the oropharynx increases as a result of changes in the mandible-advanced position. The increase in oropharyngeal volume demands greater muscular constriction to generate swallowing pressure and could lead to a decrease in reserve capacity of swallowing.
老年人吞咽障碍康复包括直接治疗，以改变口咽的三维形状，使食物团块能够安全地通过功能不良的咽。下颌位置的改变被认为会影响口咽的形状，但这种关系仍知之甚少。因此，我们研究了在正常进食的坐姿中下颌位置与口咽三维形状之间的关系。10 名健康、有牙的受试者参与了研究（平均年龄 28.1 岁）。实验性下颌位置为正中牙合位、咬合抬高位和下颌前伸位。口咽在 90°坐姿下使用口腔锥形束 CT 扫描，在获得口咽容积、高度、截面积、口咽平均截面积和会厌位置后，分析下颌位置变化对口咽的影响。与其他下颌位置相比，下颌前伸位时口咽容积和平均截面积显著增加。值得注意的是，口咽下部的容积和平均截面积显著增加。与正中牙合位相比，咬合抬高位和下颌前伸位时会厌基部的口咽高度和截面积没有显著差异。会厌在下颌前伸位时明显向前移动。本研究结果表明，在坐姿中，下颌前伸位会导致口咽容积增加。口咽容积的增加需要更大的肌肉收缩来产生吞咽压力，可能导致吞咽储备能力下降。
