Molar occlusion and jaw mechanics of the Eocene primate Adapis.
Molar occlusion and jaw mechanics of the Eocene primate Adapis.
复制标题
始新世灵长类阿达皮斯的磨牙咬合和颌力学。
DOI：
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发表时间：
1972
影响因子：
2.8
通讯作者：
P. Gingerich
中科院分区：
文献类型：
--
作者：
P. Gingerich
描述了始新世灵长类动物大Adapis magnus臼齿的磨损面。这些磨损面上的条纹表明咀嚼时下颌运动的三个独立方向。一个方向对应于咀嚼的第一阶段，涉及下颌骨的垂直回缩。其余两个方向对应于涉及下颌骨横向运动的咀嚼的第二阶段的颊侧和舌侧阶段。
下颌内收的力学分析了咀嚼的正向收缩和横向阶段。在垂直后缩阶段，咬合力的最大分量是由颞肌直接作用于食物，下颌骨起连接作用而不是杠杆作用。一个几何参数表明，在咀嚼的横向阶段咬合力是由颞肌的两侧，同侧的内侧和外侧翼肌，和对侧咬肌。
Wear facets on molars of the Eocene primate Adapis magnus are described. Striations on these wear facets indicate three separate directions of mandibular movement during mastication. One direction corresponds to a first stage of mastication involving orthal retraction of the mandible. The remaining two directions correspond to buccal and lingual phases of a second stage of mastication involving a transverse movement of the mandible.
The mechanics of jaw adduction are analysed for both the orthal retraction and transverse stages of mastication. During the orthal retraction stage the greatest component of bite force is provided by the temporalis muscles acting directly against the food with the mandible functioning as a link rather than as a lever. A geometrical argument suggests that during the transverse stage of mastication bite force is provided by the temporalis muscles of both sides, the ipsilateral medial and lateral pterygoid muscles, and the contralateral masseter muscle.