DYNAMICS OF ELECTROMYOGRAPHY INDI-CATORS MUSCULUS MASSETER MUSCULUS TEMPORALIS AND UNDER THE INFLUENCE OF STIMULATION MUSCLE GROUPS THAT ENSURE COORDINATION THIN CHEWING MUSCLES DURING TREATMENT OF ORTHO-PEDIC TOTALLY EDENTULOUS

Objective. Increase in the level of adaptive capacity of oral cavity organs to the prosthodontic treatment of patients with completely absent dentition is one of the urgent problems of modern dentistry. In order to increase the level of adaptability to complete removable laminar dentures, a set of standard samples according to H. Landt was used to test the ability for precise coordination of masticatory muscles – the MA-test (Muscular-Ability) as a means of a group of muscles stimulation providing precise coordination of masticatory muscles. This adaptation process was called MA-stimulation. Methods. The level of adaptive capacity of the oral cavity organs was studied using surface electromy-ography musculus masseter and musculus temporalis. The criteria for evaluation of the activity of the mastica-tory muscles biopotential were the indices of the total amplitude of the musculus masseter and musculus tem-poralis (μV) work when performing functional tests: 1) in a state of relative physiological rest; 2) in case of maxi-mal jaws compression; 3) in case of maximal jaws com-pression with cotton rolls. In order to achieve the objec-tive, we examined 90 patients with completely absent dentition who applied for the repeated prosthodontic retreatment. The patients' age ranged from 45 to 89 years. The patients were divided into two groups. Group I included 30 patients who underwent the prosthodontic treatment without preliminary MA-stimulation. Group II included 60 patients who underwent MA-stimulation for 14 days before the prosthodontic treatment. According to electromyography results, the indi-ces of total amplitude of musculus masseter and musculus temporalis (μV) work decreased by 23.5% (p<0.001) in a state of relative physiological rest after 14 days of MA-stimulation, by another 14.1% (p<0.05) in 1 month after the prosthodontic treatment, by another 9.2% (p<0.05) in 3 months after the prothodontic treatment; this index increased by 29.8% (p<0.05) in case of maximal jaws compression after MA stimulation, the increase reached 36.4% (p<0.05) and 44.7% (p<0.05), respectively, in 1 and 3 months compared to period before the treatment; this index increased by 26.8% (p<0.05) in case of maximal jaws compression with cotton rolls after MA stimulation, the increase reached 27.1% (p<0.05) and 42.2% (p<0.05), respectively, in 1 and 3 months in comparison with the period before the treatment. Results. The patients of Group I did not undergo MA-stimulation. The indices of total amplitude of musculus masseter and musculus temporalis (μV) work in a state of relative physiological rest decreased by 18.1% (p<0.05) in 1 month after the prothodontic treatment and by another 20.9% (p<0.001) in 3 months. The increase in this index was not noted in 1 month after the prothodontic treatment in case of maximal jaws compression. However, it increased by 25.2% (р<0.05) in 3 months in comparison with the period of “1 month”. The increase in total amplitude of musculus masseter and musculus temporalis (μV) work in case of maximal jaws compression with cotton rolls by 25.1% (p<0.05) was observed only in 3 months after the prothodontic treatment in comparison with the period before the treatment. Conclusions. The results of the research showed that MA stimulation contributed to the rapid active in-crease in adaptive processes to the use of complete re-movable laminar dentures complete removable laminar dentures in the patients with completely absent dentition.