PECULIARITIES OF USING ORTHODONTIC ACTIVATORS FOR DISTAL BITE AND APPLICATION OF RETENTION APPARATUS TO RETAIN RESULTS
Authors: Flis P.S. , Omelchuk M.A. , Rashchenko N.V. , Tsyzh A.V. 
Published: August 2020

Relevance. Distal occlusion is accompanied by certain morphological, functional, and aesthetic changes, in which there are disorders of external respiration, speech disorders, dysfunction of chewing, and swallowing. Today the problem of treatment of occlusion anomalies is not completely solved. The presence of errors and complications in the treatment of distal occlusion, the presence of recurrence of the disease in the form of a double occlusion, which necessitates repeated, and often unsuccessful treatment, indicates that the problem is still far from its final solution.
Objective: to investigate the effectiveness of the use of orthodontic activators for the treatment of distal occlusion and retention devices to maintain the results of treatment.
Materials and methods. 126 children aged 9-12 years with distal occlusion are divided into 2 groups. Group I (n=63) – children with distal occlusion and physiological type of respiration; Group II (n=63) – children with distal occlusion and pathological (oral) type of breathing. Conducted clinical, myographic, and anthropometric studies. All patients were treated by wearing a removable functional two-jaw orthodontic activator for at least 16 hours a day, with mandatory use during sleep, for 6 months. In addition to this hardware method of treatment, preventive measures were prescribed: myogymnastic and breathing exercises. The correction of the orthodontic activator was performed once a month. A control electromyographic study to determine the effectiveness of treatment was performed 3 months after the start of treatment (selectively, in some patients - also in the sixth month of treatment). Nylon floss, to keep the teeth in the achieved position.
Results. The study of the designs of retention devices and comparison of their effectiveness showed that after active orthodontic treatment the most effective retention can be achieved by using a retainer made of flex wire and nylon thread impregnated with liquid photopolymer. The most optimal way to fix the fixed retention apparatus was as follows: complete completion of the active period of treatment; control of fissure-tubercle contact; professional teeth cleaning; conducting X-ray control to identify the position of the roots of the teeth; production of gypsum models and their fixation in the occluder; detection of contact points of the frontal group of teeth; detection of the location of the retainer in the oral cavity; making a retainer indirectly; fixation of the retention apparatus in the oral cavity. Our proposed method of manufacturing and fixing non-removable retainers with the use of nylon thread allows us to achieve reliable long-term retention of the achieved positive results after active orthodontic treatment.
Analysis of the study data of children aged 9-12 years with distal occlusion and pathological (oral) type of respiration compared with the control group showed an increase in all measured EMG parameters for the temporalis muscles (in the range of 16-31.1±3.12%) and reduction - for the actual masticatory and circular muscles of the mouth (in the range of 17.0-29.8±3.09% and 16.8-35.9%, respectively). The total deviation of the values of the obtained indicators from the normative ranges from 16.0 to 35.9 ±2.56%. These abnormalities can be seen as a manifestation of the formation of a pathological muscle reaction, accompanied by negative changes in the appearance of the patient.
The design of a removable functionally acting two maxillary orthodontic activators for simultaneous treatment of distal occlusion and dysfunction of masticatory and facial muscles in children with physiological and pathological types of respiration has been developed. It consists of a monoblock and a vestibular plate, monolithically connected to each other.
Conclusions. In patients with distal occlusion, treatment with a removable functional two-jaw orthodontic activator helps to restore myodynamic balance in the dental system, resulting in improved patient facial expression, self-esteem, and quality of life. Wearing non-removable retainers with the use of nylon thread allows us to achieve reliable long-term retention of the achieved positive results after active orthodontic treatment.