The dissertation is devoted to increase of efficiency of orthodontic retention in patients after removal of bracket-system taking into account the morpho-functional state of dento-jaw system and postural balance.
The most frequent and significant "risk factors" of recurrence of malocclusion in the retention period are established and their prevalence is analyzed, the main strategic and tactical errors are identified during orthodontic treatment of patients, which lead to complications during the retention period. The morpho-functional status of patients in the retention period was found and was characterized by an imbalance in the work of chewing and temporal muscles – in 71.2% of observations; dysfunction of TMJ – 58,4%; changing of the position of 1-2 teeth – 22.4% of patients. In the main and control groups at the beginning of the retention stage, changes in the stabilized postural balance indices were detected, in contrast to the test group (p <0.01).
On the basis of definite violations of the functional state of the tooth-jaw system of the patients of the Study group, we proposed a certain algorithm for the orthodontic retention tactics, which consisted in the application of a removable appliance of new design. Removable appliance, which is called corrector position of the lower jaw, is fixed on the lower jaw, has a shortened basis from the tongue and vestibular sides, promotes the preservation of the functional load on the occlusal surface of the teeth, does not reduce the volume of the oral cavity, and can also be used for therapeutic exercises for the muscles of the tongue and provides correction of the position of the mandible in three planes. For making an appliance we used the method of determining the optimal individual occlusion height. For this method, postural kinesiological tests are performed in the state of physiological rest and maximum clenching of the teeth on the left and right sides. During control visits, the patients in the Study and Control groups were perfomed a clinical examination, EMG of masticatory muscles, and stabilitometry testing in 3 and 6 months and one year.
In patients of the Study group in 3 months of functional therapy in the retention period, symmetry in the indexes of activity of the temporal and masseter muscles on the right and left sides in the tests of maximal clenching of the teeth, protrusion and retrusion of the mandible (p <0.01) was found. Increasing of the bioelectric activity of the muscles of the working side over the balancing side in the samples of clenching of the teeth on the left and right sides was observed (p <0.01). The tendency to normalize the functional activity of masticatory muscles was maintained after the completion of functional therapy. At the same time, in the control group there was a violation of symmetry in the work of masticatory muscles on the left and on the right, as in the beginning of the retention stage.
The effectiveness of the algorithm of the orthodontic retention tactic in patients after the removal of the bracelet system is substantiated and clinically confirmed. Postural and muscular balance of the maxillofacial system in the Study group after 6 months of functional therapy was improved significantly and approached the norm, unlike the control group, in which the functional state of the tooth-jaw system and postural body balance did not improve. After a year of observation in the main group, no cases of change in the position of teeth and manifestations of TMJ dysfunction were identified.
