INCISAL BITING IN THE MOUNTAIN BEAVER (APLODONTIA-RUFA) AND WOODCHUCK (MARMOTA-MONAX)
INCISAL BITING IN THE MOUNTAIN BEAVER (APLODONTIA-RUFA) AND WOODCHUCK (MARMOTA-MONAX)
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DOI：
10.1002/jmor.1052260106
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发表时间：
1995-10-01
影响因子：
1.5
通讯作者：
DRUZINSKY, RE
中科院分区：
文献类型：
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作者：
DRUZINSKY, RE
对两种啮齿类动物（阿plodontia rufa和旱獭）的同步记录的电影x线片和肌电图的分析表明，切齿功能时的下颌运动和肌肉活动与咀嚼时的运动和肌肉活动明显不同。切咬时的运动主要沿着中线，并伴有下颌内收肌的对称活动。大多数的咬循环并不在上门牙和下门牙接触时结束。当接触发生时，下门牙会沿着上门牙的舌面被拖拽。修剪，或尖对尖咬合的上门牙和下门牙，没有观察到。在a . rufa和M. monax中都记录了下门齿的锐化行为，这可能是齿类动物独有的行为。在锐化过程中，下门牙的舌面被拖过上门牙的尖端，产生舌磨损面。像切牙一样，锐化运动主要局限于中线，尽管在一些锐化周期中可能会有横向运动。锐化周期是有记录的哺乳动物中最快速的周期运动之一，毛茛的平均锐化频率为11周期/秒，毛茛的平均锐化频率为8周期/秒。(C) 1995 Wiley-Liss, Inc。
Analysis of synchronously recorded cine-radiographs and electromyograms in two rodents (Aplodontia rufa and Marmota monax) demonstrates that jaw movements and muscle activities during incisal functions are distinctly different from those found during mastication. Movements during incisal biting are primarily along the midline, accompanied by symmetrical activity of the jaw adductor muscles. Most biting cycles do not end in contact between upper and lower incisors. When contact does occur, the lower incisors are dragged along the lingual surfaces of the upper incisors. Cropping, or tip-to-tip occlusion of upper and lower incisors, was not observed.Sharpening of the lower incisors, a behavior which may be unique to the Rodentia, was recorded in both A. rufa and M. monax. During sharpening, the lingual surface of the lower incisor is dragged across the tip of the upper incisor producing a lingual wear facet. Like incisal biting, sharpening movements are primarily confined to the midline, although there may be lateral movements in some sharpening cycles. Sharpening cycles are among the most rapid cyclic movements recorded in mammals, as the mean frequencies of sharpening are 11 cycles/s in A. rufa and 8 cycles/s in M. monax. (C) 1995 Wiley-Liss, Inc.