Dentoalveolar anomalies and modern views on the mechanisms of local stress-modeling effect of orthodontic appliances on the periodontal tissues (a literature review)

The aim of the study was to highlight the results of modern scientific developments in tracing the mechanisms of local stress -mode-ling effect of orthodontic appliances on the oral cavity and periodontal tissues during the active period of orthodontic treatment.Materials and methods. The research methodology was implemented in the collection and analysis of scientific results on the stress-modeling effect of orthodontic appliances in patients with dentoalveolar anomalies obtained from the processed sources - published full-text articles of original and fundamental research by national and foreign authors based on the evidential databases MEDLINE / PubMed, PMC, Scopus, Web of Science, Cochrane, Google Scholar, ResearchGate and other scientific and practical resources.Results. The main components of the stress-modeling effect of fixed orthodontic appliances on the oral cavity, and particularly on the periodontal tissues, were analyzed. The proportion of various complications is quite high and ranges from 32.7 % to 50.0 % of all cases. The development of oxidative stress during orthodontic treatment is potentiated by microcirculatory disorders and hypoxia of the periodontal tissues. The peculiarities of the periodontal cellular complex reaction, which has the ability to bear stress generated in the actin cytoskeleton by direct mechanical stimulation, to extracellular matrix proteins, affecting the three-dimensional organization of the extracellular matrix and its remodeling, have been traced. The role of lipid peroxidation, antioxidant system and enzymatic reaction of oral and crevicular fluids was also defined.Conclusions. The development of oxidative stress during orthodontic treatment can be caused by local and systemic exposure to metals, corrosion processes in particular; by inflammation of periodontal tissues due to poor oral hygiene and activation of periodontal pathogenic microflora; by aseptic inflammation in the periodontal ligament due to the use of mechanical force. Certain enzymes of the oral fluid, in particular lactate dehydrogenase, can act as a sensitive marker of changes in the periodontal ligament metabolism during orthodontic teeth movement. The localization and nature of free radical pathology are largely caused by the nature of an exogenous inducer of lipid peroxidation and the genotypic characteristics of antioxidant system. It is this ratio that determines the initiation and further chain branching of free radical reactions. Without normalization of all pathogenetic links, successful treatment of inflammatory and dystrophic-inflammatory diseases of the periodontal tissues, in particular in orthodontic patients, is impossible.