口唇圧と不正咬合

Pressure from the lips on the teeth and malocclusion.

抄録

様々なタイプの不正咬合を持つ84人の子供（7歳から16歳）を対象に、口唇の強さと口唇圧（唇から歯への圧力）の関係を調査した。口唇強度はダイナモメーターで記録した。口唇圧は、安静位、クリスプブレッドを咀嚼・嚥下している時の上下の中切歯で測定した。口唇圧の測定には、口腔内マウスピースで水を満たした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た。口唇の筋活動は筋電図で記録した。咬み合わせと顔面の形態は、歯型と横顔のセファログラムで調べた。口唇の強さと口唇圧との間に相関はみられなかった。口唇強度は、Angle Class II, Division 1の不正咬合の小児では、Class Iの不正咬合の小児よりも低かった。一方、上顎切歯に対する口唇圧は、II級1号ではI級不正咬合よりも高く、II級2号では最も低かった。この結果は、口唇から歯への圧力は切歯の位置の結果であることを示唆している。

The relationship between lip strength and lip pressure (pressure from the lips on the teeth) was studied in 84 children (aged 7 to 16 years) with varying types of malocclusion. The lip strength was recorded with a dynamometer. The lip pressure was measured on the upper and lower central incisors in the rest position, and during chewing and swallowing of crispbread. The lip pressure measurements were made with an extraoral pressure transducer incorporated in a water-filled system with an intraoral mouthpiece. The muscle activity of the lips was recorded electromyographically. Bite and facial morphologies were studied on dental casts and profile cephalograms. There was no correlation between lip strength and lip pressure. Lip strength was lower in children with Angle Class II, Division 1 malocclusion than in children with Class I malocclusion. The lip pressure on the upper incisors, on the other hand, was higher in Class II, Division 1 than in Class I malocclusion, and was lowest in children with Class II, Division 2 malocclusion. The findings suggest that the pressure from the lips on the teeth is a result of the incisor position.