EN
The retrospective analysis of data on oral cavity clinical status in relation to microbiota species composition is presented. The research regards patients of different age, with and without congenital malformation, pretreatment assessed for occurrence of pathological changes in the masticatory system. Samples of the swabs collected from each patient (from dental plaque, periodontium and dental pockets) were used for identification of oral protozoans in wet slides and stained preparations; additionally, transmission electron microscope examination was performed. The material was used for in vitro cultures to identify bacteria strains. Clinically, intensity of tissue deteriorations was higher in patients with a congenital disease. Alive Trichomonas tenax and Entamoeba gingivalis, species with confirmed pathogenic impact on oral cavity and neighboring structures, were detected with higher prevalence in older patients. Enterococci, Staphylococcus aureus, various Enterobacteriaceae were more frequently detected in patients with somatic and mental retardations; in mouths of those patients, Klebsiella pneumonia and Pseudomonas aeruginosa opportunistic strains occurred. Masticatory system abnormalities favor colonization of oral cavity by exogenous species and dissemination of infections, especially dangerous for patients with congenital diseases. Oral microbiota assessment and preventive measures may be helpful to avoid subsequent peri-surgery complications.