Histochemical Study of Rabbit Masseter Muscle: The effect of the alteration of food on the muscle fibers

抄録

The purpose of the present study is to investigate the effect of a fine-grained food on the composition and development of the masseter fibers in the rabbits. Masseter fibers were classified as one of three types based on their levels of staining for myofibrillar ATP ase. In Type I (slow) fibers, the diameter and ratio of the fiber was most remarkably decreased by the fine-grained diet. The ratio of type IIa and IIb fibers in the fine-grained diet subjects were increased. The diameter of all fibers in the deep region showed significant decrease. In the superficial region, the diameter of Type I and IIa fibers decreased; however, the diameter of Type IIb increased. These findings suggest that the histochemical characteristics of the masseter muscle are reflected in size and composition of the muscle fibers by decreasing the masticatory loads.