Morphometric analysis of the mandible in growing rats with different masticatory functional demands: adaptation to an upper posterior bite block
Morphometric analysis of the mandible in growing rats with different masticatory functional demands: adaptation to an upper posterior bite block
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DOI：
10.1111/j.1600-0722.2004.00129.x
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发表时间：
2004-06-01
影响因子：
1.9
通讯作者：
Kiliaridis, S
中科院分区：
文献类型：
--
作者：
Mavropoulos, A;Bresin, A;Kiliaridis, S
功能性矫治器使下颌向前和/或向下移位，导致口面部软组织（包括肌肉）拉伸。由此产生的力直接或间接传递到下面的牙骨骼组织。本研究的假设是，咬开器具的插入会影响大鼠下颌骨生长过程中的横向形态，而且这种影响取决于咀嚼功能的需求。将一百零四只4周龄雄性白化大鼠分为两组，分别喂硬食和软食。 2周后，每个实验组中的一半动物安装上后部块，4周后将其处死。他们的左半下颌骨被透照、放大拍照并在屏幕上数字化。总共用了170个点来绘制下颌骨的侧面轮廓。除了对牙槽突高度产生抑制作用外，上咬合块还会导致髁突倾斜度、冠突长度和咬合面倾斜度发生显着变化。咀嚼功能需求以累加的方式影响这种适应。结果提出了一个问题：根据口面部软组织的特征，后牙咬合块的正畸治疗是否会对下颌骨产生不同的影响。
Functional appliances displace the mandible forward and/or downward, causing a stretching of the orofacial soft tissues, muscles included. The resulting forces are directly or indirectly transmitted to the underlying dento-skeletal tissues. The hypothesis underlying the present investigation was that the insertion of a bite-opening appliance influences the lateral morphology of the rat mandible during growth, and that, moreover, this influence depends on the masticatory functional demands. One-hundred and four 4-wk-old male albino rats were divided into two groups, fed a hard and soft diet, respectively. After 2 wk, half of the animals in each experimental group were fitted with upper posterior blocks, and 4 wk later they were killed. Their left hemi-mandibles were transilluminated, photographed under magnification, and digitized on screen. A total of 170 points were used to draw the lateral outline of the mandible. In addition to the inhibitory effect on the height of the dento-alveolar process, the upper bite block resulted in significant changes in the condyle inclination, the length of the coronoid process, and the occlusal plane inclination. Masticatory functional demands influenced this adaptation in an additive way. The results raise the question of whether orthodontic treatment with posterior bite blocks might have different effects on the mandible, depending on the characteristics of the orofacial soft tissues.