Nonlever action of the mandible: the return of the hydra.
Nonlever action of the mandible: the return of the hydra.
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下颌的非杠杆作用：九头蛇的回归。
DOI：
10.1002/ajpa.1330740304
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发表时间：
1987
影响因子：
2.8
通讯作者：
Hylander,WL
中科院分区：
文献类型：
--
作者：
Picq,PG;Plavcan,JM;Hylander,WL
最近，Taylor（1986）提出了一项分析，试图证明下颌骨不起杠杆作用。他指出，在单侧咬合过程中，位于咬合侧（工作侧）的髁突位于下颌窝（WF）。因此，如果下颌骨要起到杠杆的作用，那么工作侧髁突必须在工作侧MF的顶部上施加很大的力。由于对这部分MF的检查显示，骨骼非常薄，无法承受咀嚼过程中的这种应力，泰勒得出结论，下颌骨不能发挥杠杆作用。我们认为泰勒的论点存在严重缺陷。这一点在他没有讨论任何反对非杠杆作用的论点（Hylander，1975; Smith，1978;步行者，1978; Picq，1983），以及在等长咬合和咀嚼过程中下颌髁实际上受到载荷的数据（Hylander，1978，1979 a; Bennan等，1981年）。反对下颌骨的非杠杆作用的最简单和最有力的论据是门齿咬合。在这种情况下，通过肌肉和反作用力的对称性简化了对钳口上的力的分析。“在人类中已经证明，在切咬过程中，下颌咬合力主要是垂直方向的（Hylander，1978）。由于合颌肌肉力的合力（根据纤维取向和EMG数据）不能具有与切牙咬合力相等且相反的合力（参见图10）。Hylander和约翰逊，19851，髁必须加载以保持静态平衡。因此，我们有一个明确的例子，其中下颌骨作为一个修改后的I11类杠杆与两个髁加载。
Recently Taylor (1986) presented an analysis which attempted to demonstrate that the mandible does not function as a lever. He noted that during unilateral clenching the condyle situated on the side being clenched (the working side) is located in the mandibular fossa WF). Therefore, if the mandible is to function as a lever, then the working-side condyle must exert a great deal of force on the roof of the working side MF. Since an examination of this part of the MF reveals that the bone is very thin and could not withstand such stresses during mastication, Taylor concluded that the mandible cannot function as a lever.We feel that Taylor's argument is seriously flawed. This is most dramatically illustrated by his failure to discuss any of the arguments against nonlever action (Hylander, 1975; Smith, 1978; Walker, 1978; Picq, 1983), and by data which demonstrate that the mandibular condyles are in fact loaded during isometric biting and mastication (Hylander, 1978, 1979a; Brehnan et al., 1981). The simplest and strongest argument against nonlever action of the mandible can be made for incisor biting. In this situation the analysis of forces on the jaw is simplified by the symmetry of muscle and reaction forces.'It has been demonstrated in humans that the mandibular bite force during incisal biting is primarily directed vertically (Hylander, 1978). Since the resultant of the jawclosing muscle force (according to fiber orientations and EMG data) cannot have an equal and opposite resultant to the incisal bite force (cf. Hylander and Johnson, 19851, the condyles must be loaded in order to maintain static equilibrium. Thus we have a clear example in which the mandible functions as a modified class I11 lever with both condyles loaded.
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人类下颌：杠杆还是连杆？
影响因子：
2.8
作者：
W. Hylander
通讯作者：
W. Hylander
澳大利亚抗原（HBsAg）传播的遗传假说。
影响因子：
2.8
作者：
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通讯作者：
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DOI：
10.1016/0030-4220(72)90361-1
发表时间：
1972
期刊：
Oral surgery, oral medicine, and oral pathology
影响因子：
--
作者：
David Poswillo;David Poswillo
通讯作者：
David Poswillo
下颌骨的非杠杆作用。
影响因子：
2.8
作者：
R. M. Taylor
通讯作者：
R. M. Taylor
灵长类动物的下颌生物力学和颞下颌关节功能。
影响因子：
2.8
作者：
R. Smith
通讯作者：
R. Smith