Effects of facial denervation on the growth of the maxillo-facial region
Effects of facial denervation on the growth of the maxillo-facial region
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面部去神经支配对颌面部生长的影响
DOI：
10.5794/jjoms.34.522
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Y. Kitagawa
中科院分区：
文献类型：
--
作者：
Y. Kitagawa
本研究试图阐明单侧面神经切断对颌面部生长的影响，通过肌肉组织化学研究，头影测量分析，热成像，血管造影检查。3周龄荷兰-波兰兔和wister大鼠进行了右侧面神经解剖。去神经后，家兔的面部偏向瘫痪的右侧，瘫痪侧的颌面部骨骼相当萎缩。而失神经后大鼠面部向左侧偏移，颌面部骨骼未受影响。兔子只能够咀嚼未瘫痪的一侧，而老鼠能够咀嚼未瘫痪和瘫痪的两侧。因此，本研究采用组织化学的方法，对咀嚼肌和口轮匝肌的肌纤维进行了研究。根据肌原纤维ATP酶的活性，这些肌纤维被分为1型（慢肌颤）和2A型或2B型（快肌颤）。结果表明，在兔咬肌中，右侧肌肉的2A型纤维较多，而1型纤维较少且较小，与左侧咬肌相比，NADH活性较低。这表明右面部去神经支配后咀嚼时右咬肌的相对废用。1型纤维最适合于咀嚼和姿势支撑所需的中等力量的持续收缩。因此，右咬肌中1型纤维的比例和直径减小可能是由于这些纤维的募集模式响应于改变的颌功能而持续改变。家兔下颌畸形可能是由于左右咬肌功能不平衡所致，而大鼠咬肌1型肌纤维缺乏。在失神经支配的兔和大鼠口轮匝肌中，均观察到2型优势和群体萎缩等神经源性改变。
The present study was attempted to elucidate the effects of unilateral facial denervation on the growth of the maxillo-facial region by means of a histochemical study of the muscles, a cephalometric analysis, by thermography, and by angiographic examination.Three-week-old Dutch-Polish rabbits and wister rats were subjected to dissection of the right facial nerve. After this denervation, the face of the rabbit deviated to the paralyzed right side, and the maxillo-facial skeleton on this paralyzed side was fairly atrophied. In contrast, the face of the rat after denervation deviated to the left side, and the rnaxillo-facial skeleton was not affected. Rabbits were able to masticate only on the unparalyzed side, whereas the rats were able to masticate on both the unparalyzed and paralyzed sides. This suggested that the mechanism of these facial deformities are related to their masticatory patterns, and so the fibers of the masseter and the orbicularis oris muscles then were investigated histochemically. These muscle fibers were classified into type 1 (slow twitch) and type 2A or type 2B (fast twitch) on the basis of the activity of the myofibrillar ATPase.The results achieved indicated that in the rabbit masseter, the right muscles had more type 2A and fewer and smaller type 1 fibers, and a lower NADH activity when compared to the left masseter muscles. This indicates a relative disuse of the right masseter muscles when chewing after right facial denervation. Type 1 fibers are best adapted for sustained contractions of moderate force which are required for chewing and postural support. Thus, a reduced proportion and diameter of type 1 fibers in the right masseter muscles may result from a sustained alteration in the patterns of recruitment of these fibers in response to the altered jaw function. The jaw deformity in the rabbit may result from a functional imbalance between the right and left masseter muscles.As for rat masseter muscles, type 1 fibers were scarce. No functional imbalance was found between the right and left muscles.In the denervated orbicularis oris muscles of both the rabbit and the rat, neurogenic changes such as type 2 predominancy and group atrophy were observed.