重症心身障害児者において下顎の安定性が嚥下動態に及ぼす影響

Effects of jaw stability on pharyngeal swallow in patients with severe motor and intellectual disabilities

　重症心身障害児者における下顎の安定性が咽頭期嚥下に与える影響を探ることを目的に，口腔期の舌運動(前後・上下)の違いによる嚥下時の下顎運動および舌骨運動の差異を比較した．対象は重症心身障害児者10名とし，口腔期の舌運動が前後動である5名(男性4名，女性1名：15.8±20.6歳)を前後動群，上下動である5名(男性2名，女性3名：27.2±16.2歳)を上下動群と割付けた．対象者のペースト食品3〜5mlの嚥下を嚥下造影検査で撮影し，下顎と舌骨について運動方向(垂直方向，水平方向)ごとの移動距離および移動時間を計測した．結果，下顎運動では，下制および後退距離が上下動群に比べて前後動群で長かった(p＝.009)．舌骨運動では，最大挙上位(p＝.007)および最大前進位停滞時間(p＝.011)が上下動群に比べて前後動群で短かった．

　これより，前後動群は嚥下時に下顎の固定が不十分なため，舌骨の最大挙上位および最大前進位における停滞時間が短かったと考えられた．

　This study investigated the effects of jaw stability on pharyngeal swallow by analyzing jaw and hyoid bone movement during swallow in patients with severe motor and intellectual disabilities (SMID). Ten patients with SMID underwent videofluoroscopic examination of swallowing while swallowing 3 to 5 ml of paste food. Five patients have suckling pattern (tongue moves forward and backward) during feeding, and 5 have sucking pattern (tongue moves up and down) during feeding. The range of movement of the jaw and hyoid bone were measured in two directions, horizontal and vertical, and the timing of the onset and termination of movement in each direction was timed using frame-by-frame analysis. The distance of downward and backward movement of the jaw was significantly longer in the suckling group (p=.009). The duration of maximum upward (p=.007) and forward (p=.011) displacement of the hyoid bone was significantly shorter in the suckling group. The results suggest that instability of the jaw shortens the duration of the maximum upward and forward displacement of the hyoid bone.