[Changes in the masticatory muscles, periodontal tissues and the pharyngeal ring in Wistar rats subjected to chronic psychophysical stress].

Experimental study, performed in 120 male Wistar rats, using histological and morphometric methods, has demonstrated changes of the oral tissues in response to chronic psychophysical stress (dosed swimming). Masticatory muscle showed the foci of non-infectious inflammation, dystrophic changes of muscle fibers and contractures. Periodontal ligament demonstrated the disturbances of microcirculation, with the pronounced congestion of the venous portion, local hemorrhages, changes in the orientation of collagen bundles and their deformation. In the tissues of the pharyngeal ring, the reduction in the number of lymphocytes was detected, as well as a progressing loosening of connective tissue, and a decrease in the number of non-degranulated mast cells as compared to similar parameters in the control group. The intensity of these manifestations was dependent on the level of physical load and individual adaptation capacity of an animal. The changes of the oral tissues detected in this study, may become an etiopathogenetic basis for the development of chronic inflammatory periodontal disease.