Functional Analysis of the Temporal Muscle during Open-Close Movement Using an Autonomous Jaw-Movement Simulator

为了阐明下颌运动的控制机制，我们开发了一个灵活的下颌运动模拟器，JSN/ID，它结合了电缆肌腱直流伺服驱动器，模拟咬肌，颞肌，翼外肌和二腹肌。在阻抗控制机制下，利用咬合力、齿接触、索张力和索长度等数据对驱动器进行自适应控制。为了在模拟器上实现更逼真的开闭运动，我们引入了一个控制假设，即在闭合过程中，下颌水平位置是由颞肌后部和翼外肌的对抗活动决定的，这一假设通过颞肌后部致动器的阻抗控制和翼外肌的对抗张力控制来实现。致动器以以下方式激活，以免与钳口的解剖学和生理学知识相矛盾。使质量 ...更多信息 为了施加咬合力，仅在咬合期间激活TER致动器。在阻抗控制下的前颞肌致动器单独负责确定在关闭期间下颌骨的垂直位置，并在咬合期间支持咬肌致动器。在开放过程中，二腹肌和外侧翼肌致动器被共同激活以使下颌骨下降。两个致动器都是在张力控制下驱动的，这是由于相应肌肉中缺乏肌梭。实验结果表明，上述控制方案可以在模拟器上产生可再现的逼真的开合运动，而较少激活后颞肌控制的α-γ联动的参考实验显示了动力学不稳定性，特别是在闭合阶段。所有这些都表明，通过控制颞后肌的位置和对抗翼外肌的张力控制，有可能在闭合过程中稳定下颌骨。这种控制方案的一个替代方案是采用两块肌肉的过度共同激活，以使下颌头的位置不那么柔顺。然而，这几乎是不可接受的，因为没有这样强的活动中观察到的两个肌肉在close.Physiological认证所提出的控制方案是一个任务，应该在随后的研究中处理。少

In order to clarify the control mechanism of jaw movements, we developed an autonomousjaw-movement simulator, JSN/ I D, which incorporates cable-tendon DC-servo actuators, simulating the masseter, temporalis, lateral pterygoid and digastric muscles. The actuators were controlled adaptively under an impedance-control mechanism, utilizing data of bite-force, tooth contact, cable-tension and cable-length. In order to achieve more life-like open-close movement on the simulator, we introduced a control hypothesis that during closing, the horizontal mandibular position is determined by antagonistic activities of the posterior portion of the temporalis muscles and the lateral pterygoid muscles.This hypothesis was materialized by an impedance control of the posterior temporalis actuators and an antagonizing tension-control of the lateral pterygoid muscles. The actuators were activated in the following manner, so as not to contradict anatomical and physiological knowledge of the jaws. The masse … More ter actuators were activated merely during biting, in order to exert bite force. The anterior temporalis actuators under an impedance control were solely responsible to determine the vertical position of the mandible during closing, and supported the masseter actuator during biting. During opening, the digastric and lateral pterygoid actuators were co-activated to descend the mandible. Both actuators were driven under a tension control, due to the lack of the muscle spindles in corresponding muscles. At rest, all the actuators functioned as a weak elastic body like actual muscles.Experimental results demonstrated that the afore-mentioned control scheme can produce a reproducible life-like open-close movement on the simulator, while referential experiments with less activation of the alpha-gammalinkage of the posterior temporalis control showed the kinetic instability, particularly in the closing phase. All these suggest a possibility of stabilizing the mandible during closing through the position control of the posterior temporalis muscles and antagonizing tension-control of the lateral pterygoid muscles. A single alternative to this control scheme is to employ an excessive co-activation of the two muscles to make the position of the mandibular head less compliant. This is hardly acceptable, however, because no such strong activities are observed in both muscles during closing.Physiological certification of the proposed control scheme is a task that should be dealt with in a subsequent study. Less