若年成人の歯にかかる舌圧のさらなる研究

Further studies of the pressure from the tongue on the teeth in young adults.

抄録

咬合がほぼ正常な若年成人20名を対象に、上下中切歯と左第一大臼歯の舌側4ヵ所で、舌から歯にかかる圧力を同時に記録した。安静位および咀嚼・嚥下時の測定は、口腔内マウスピースを装着した流体充填システムに組み込まれた口腔外圧力トランスデューサーを用いて行った。歯列弓の大きさは歯列模型から求めた。安静位での圧力の中央値は低く、上顎切歯では負圧であった。安静時の陰圧は4つの測定点すべてで数人の被験者に記録され、上顎切歯で最も多く、下顎大臼歯で最も少なかった。嚥下時の圧力は咀嚼時の圧力の2～4倍であった。測定された圧力と2年前の検査で同じ人に記録された圧力との間には有意な相関は見られなかった。様々な機能時に4つの部位で記録された圧力の間には正の相関が見られた。これは舌の大きさの影響と解釈された。圧力と歯列弓の大きさを表すパラメータとの間に比較的相関が少ないことから、歯列弓の範囲内で舌が適応的な役割を果たしていることが示唆された。

The pressures from the tongue on the teeth were recorded simultaneously in four locations lingual to the upper and lower central incisors, and left first molars in 20 young adults with largely normal occlusion. Measurements in the rest position, and during chewing and swallowing were made with an extra-oral pressure transducer incorporated in a fluid-filled system with intra-oral mouthpieces. The size of the dental arches was determined from dental casts. The median pressures in the rest position were low and negative at the upper incisors. Negative pressures at rest were recorded in a few subjects at all four points of measurement, most frequently at the upper incisors and least frequently at the lower molar. The pressures during swallowing were 2-4 times greater than those during chewing. There were no significant correlations between the pressures found and those recorded in the same individuals at an examination 2 years earlier. Positive correlations were found between the pressures recorded in the four locations during the various functions. This was interpreted as being an effect of the size of the tongue. The relatively few correlations between the pressures and the parameters describing the dental arch size indicated an adaptive role of the tongue within the confines of the dental arches.