MANDIBULAR MOVEMENT AND MUSCLE-ACTIVITY DURING MASTICATION IN THE GUINEA-PIG (CAVIA-PORCELLUS)
MANDIBULAR MOVEMENT AND MUSCLE-ACTIVITY DURING MASTICATION IN THE GUINEA-PIG (CAVIA-PORCELLUS)
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DOI：
10.1002/jmor.1051700203
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发表时间：
1981-01-01
影响因子：
1.5
通讯作者：
BYRD, KE
中科院分区：
文献类型：
--
作者：
BYRD, KE
对 C. porcellus 下颌运动和咀嚼肌肌电图 (EMG) 的光电分析表明，有双侧、单侧和啃咬周期。在双侧和单侧循环中，下颌尖在动力冲程的舌侧阶段向前、横向和向下移动，以使牙齿咬合。肌电图活动通常是不对称的，双侧周期期间颞肌的活动除外。在啃咬周期期间，下颌骨沿前后方向移动，该方向与双侧和单侧咀嚼周期期间相反。颗粒的双边和单边周期明显长于胡萝卜。除双侧周期宽度外，胡萝卜咀嚼过程中周期宽度、长度和高度的幅度均大于颗粒咀嚼过程中的周期宽度、长度和高度。咀嚼颗粒和胡萝卜期间肌电图持续时间也存在显着差异。外侧翼突在啃咬周期中表现出持续的活动。在所有 3 种周期类型中，工作侧和平衡侧之间的肌电图活动持续时间也存在显着差异。双侧循环期间平衡侧颞肌和二腹肌前腹 (ABD) 的高水平活动发生在动力冲程期间下颌旋转和下压期间。颞肌显然在关闭和动力冲程期间提供制动或补偿作用。豚鼠咀嚼模式与黄鼠和中仓鼠的咀嚼模式之间的差异显然是由于牙齿形态、咬合关系的差异以及可能是豚鼠颞肌发育不良造成的。啮齿动物群体的数量庞大且多样性为哺乳动物咀嚼的学生提供了研究和比较不同咀嚼专门化的机会。
Optoelectronic analysis of mandibular movement and electromyography (EMG) of masticatory muscles in C. porcellus indicate bilateral, unilateral and gnawing cycles. During bilateral and unilateral cycles, the mandibular tip moves forward, lateral and down during the lingual phase of the power stroke to bring the teeth into occlusion. EMG activity is generally asymmetric, with the exception of activity of the temporalis muscle during bilateral cycles. During gnawing cycles, the mandible moves in an anteroposterior direction that is opposite that during bilateral and unilateral chew cycles. Bilateral and unilateral cycles of pellets were significantly longer than carrot. With the exception of the width of bilateral cycles, the magnitude of cycle width, length and height during the mastication of carrots was greater than that during the mastication of pellets. Significant differences also exist between EMG durations during mastication of pellets and carrots. The lateral pterygoid displays continuous activity during gnawing cycles. Significant differences also exist in the durations of EMG activity between the working and balancing side during all 3 cycle types. High level activity of balancing side temporalis and anterior belly of digastric (ABD) during bilateral cycles occurs during rotation and depression of the mandible during the power stroke. The temporalis apparently provides a braking or compensatory role during closing and power strokes. Differences between Cavia masticatory patterns and those shown by Rattus and Mesocricetus are apparently due to differences in dental morphology, occlusal relationships and, possibly, the poorly developed temporalis in Cavia. The large number and wide diversity of rodent groups afford students of mammalian mastication an opportunity to investigate and compare different masticatory specializations.