【摘要】 本文利用弹性力学和材料力学中的有关公式,对正常牙齿受水平力时所产生的瞬时转动中心位置进行了理论分析,证实单根牙的瞬时转动中心位置在根尖以上0.428～0.551倍的牙根长度范围内变化,双根牙的瞬时转动中心位置在根尖以上0.136～0.412倍根长范围内变化。它们不是固定不变的点,而是随牙冠上受力点位置的变化而变化。同时推导出了牙冠受水平力时牙周膜的应力公式。当已知各种参数时,应用公式即可算出不同部位牙周膜的应力值。 本文还对口腔矫形治疗中常见的一些生物力学问题做了分析探讨。更多还原

【Abstract】 This article presents the theoretical analysis of the instantaneous rotation centre of the normal tooth affected by a horizontal force, using relevant elasticity and material mechanical formulae. The result of analysis confirms that the position of the instantaneous rotation centre of the singleroot tooth varies in the range of 0.428—0.551 times of the root length above the apex and that of the double-root tooth 0.136—0.412 times. These positions, however, are changeable to the load at the crown. A formula of stress for the periodontal membrane with the crown affected by a horizontal force was drawn. Values of stress at various parts of the periodontal membrane can be determined means of this formula with given parameters.Some biomechanial problems occured in prothetic treatment were analysed and discussed.更多还原