人咬肌和颞肌的肌构筑及生物学特性

目的：查明人咬肌和颞肌的肌构筑特征，分析两肌各部的生物力学属性，探讨其生理功能，方法：对人10侧咬肌和颞肌的构筑指数作测算和量化分析，结果：咬肌和颞肌均属多羽肌范畴，尤其是咬肌浅部内存在有多层腱板，肌纤维以浅-深两面附着于腱板上，对咬肌浅，深两部，颞肌前，后两部的肌构筑指数分别作两两比较，其构筑指数在各部间均有明显不同，其中，颞肌后部肌质量值最大，咬肌浅部次之，咬肌深部最轻，而生理横切面积则是咬肌浅部最大，依次为颞肌后部，颞肌前部，咬肌浅部和颞肌前部相近，最低者为颞肌后部，颞肌后部肌纤维最长，咬肌深部肌纤维最短，以上比较均有显著性差异。结论：咬肌深部属力量型肌，咬肌浅部和颞肌前部兼备力量和速度，而颞肌后部相对倾向于速度型肌，咬肌深部和颞肌前部在维持下颌位置和平衡中起重要作用，咬肌浅部和颞肌后部是产生咬合力和下颌快速移位的主体。

Properties of biomechanics and muscle architecture in human masseter and temporolis

Objective: To study the architectural features and the biomechanical properties of human masseter and temporolis muscles. Methods: The architecture parameters of masseter and temporolis muscles on both sides of 5 human corpes fixed in formalin for more than 1 year were measured and quantitatively analyzed. Results: Human masseter and temporolis muscles were multipennate, there existed many layers of aponeurosis to which muscle fibers attached especially within the superficial portion of the masseter. The parameters of superficial portion of the masseter were statistically different from those of the deep portion, so were those of anterior portion of temporolis from those of posterior portion; the posterior part of the temporolis was the heaviest, the deep of the masseter the lightest. The physiological cross-sectional area of the superficial part of masseter was the largest, the posterior of temporolis the second, the anterior of temporolis the third, and the deep of the masseter the smallest. Among the ratios of muscle weight vs physiological cross-sectional area in each portion of the masseter and temporolis, the ratio in the deep part of masseter was the largest, that in the posterior of temporolis the smallest, that in the superficial of the masseter was similar to that in the anterior of the temporolis. In addition, the fiber in the posterior of the temporolis was the longest and that in the deep of the masseter the shortest. Conclusion: The deep portion of masseter is designed for force production, the posterior of the temporolis for velocity production, and the superficial of the masseter and the anterior of the temporolis for both force and velocity production. The deep part of masseter and the anterior of temporolis play an important part in maintaining mandibular position and balence, and the superficial of masseter and the posterior of temporolis play a major role in producing occlusive force and mandibular fast retrusion.