初期混合歯列における口腔機能と下顎前群集との関係

Relationship between oral function and mandibular anterior crowding in early mixed dentition.

• Yoma Ohno
• Yuko Fujita
• Keirato Ohno
• Kenshi Maki

抄録

歯列の位置は、口腔周囲筋と舌の力の組み合わせによって決定されると考えられている。我々は，下顎前群集が口腔機能の発達異常と関連しているのではないかとの仮説を立てた．早期混合歯列における口腔機能と下顎前群集との関係を明らかにすること。本研究では，早期混合歯列の小児61名（男児30名，女児31名）を対象とした．参加者全員の身長，体重，最大咬合力，口唇閉鎖力，最大舌圧を測定し，歯列模型と側方セファログラムを評価した．歯列模型で評価したLittle's irregularity index (LII)を下顎前群集の指標として使用した。最大咬合力と口唇閉鎖力はLIIと有意な相関はなかったが、最大舌圧、下顎犬歯間周囲距離、上中切歯（U1）-NL角と正の相関があった（p<.05）。最大舌圧はLIIと負の相関があった(p<.05)。最大舌圧とLIIは下顎犬歯間周囲距離とU1-NL角と有意に正の相関があり、歯間角と負の相関があった(すべてにおいてp<.05)。下顎前歯の混雑は舌圧機能と直接相関し，最大咬合力と口唇閉鎖力と間接的に相関していた．

The position of the dentition is considered to be determined by a combination of forces exerted by the perioral muscles and tongue. We hypothesized that mandibular anterior crowding may be related to abnormalities in the development of oral function. To determine the relationship between oral function and mandibular anterior crowding in early mixed dentition. A total of 61 children (30 boys, 31 girls) with early mixed dentition were included in this study. Height, body weight, maximum occlusal force, lip-closing strength, and maximum tongue pressure were measured in all participants, and their dental casts and lateral cephalograms were evaluated. Little's irregularity index (LII), evaluated by dental casts, was used as an indicator of mandibular anterior crowding. Maximum occlusal force and lip-closing strength were not significantly correlated with the LII, although they were positively correlated with maximum tongue pressure, mandibular intercanine perimeter distance, and upper central incisor (U1)-to-NL angle (p < .05). Maximum tongue pressure was negatively correlated with LII (p < .05). Maximum tongue pressure and LII were significantly positively correlated with the mandibular intercanine perimeter distance and U1/NL angle, and negatively correlated with the interincisal angle (p < .05 for all). Crowding of the mandibular anterior teeth was directly correlated with tongue pressure function and indirectly correlated with maximum occlusal force and lip-closing strength.

© 2020 The Authors. Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.