Analysis of clinical data when choosing the type of retention structure after treatment with multibonding fixed orthodontic equipment

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Relevance. In recent years, there has been a positive trend in the use of various
structural solutions for intraoral retainers in the practice of orthodontists. The individual
approach and the complexity of clinical cases revealed the need to classify retention devices
by type of fixation. Among removable designs, the Osamu retainer is the most popular, and
the classic Holi retainer is also often used. As for non-removable fixed retainers, they come
in two types: 1) stranded wire with a cross section of 0.03 inches; 2) braided arc with a
diameter of 0.0215 inches. The increase in the number of recurrences in orthodontic practice
indicates a serious problem in achieving stable treatment results in adolescents and adults.
Therefore, this study is relevant, since the selection and clinical use of all types of retention
devices is a difficult task, especially in the absence of a clinical protocol for the management
of the retention period.

Object. The purpose of our work was to study modern approaches to the use of
various designs of retainers in the orthodontics clinic to reduce the percentage of recurrence
of dental anomalies and deformities.

Research objectives:
1. To analyze the methodology of standard retention methods in orthodontic patients.
2. Evaluate the quality of the combination of removable and non-removable types of
retention.
3. To study the time parameters of the retention period when using different designs.

Materials and methods:
In the course of the work, a comprehensive diagnosis and analysis of the results
of the retention period was used with the involvement of several types of retainers after an
active period of treatment using modern non-removable multibonding equipment in 95
individuals with violations of the position of individual teeth, anomalies of dentition and bite.
The study period was 12-24 months.
In the course of the research work, the following methods were used:
- Clinical examination method.
- Biometric characteristics of diagnostic models of patients' jaws.
- Radiation research methods.
- Photometric method.
- Statistical analysis of the research results.
The standardized retention methods used at this stage in orthodontic patients after
the bracket system show satisfactory long-term results. Usually used: 1) a monofilament
retainer of large cross-section with fixation in the canine region, providing transversal
stabilization of the dentition; 2) a stranded twisted wire retainer of round or rectangular crosssection fixed to six front teeth; 3) removable retainers of various design solutions that
stabilize the entire dentition.
The retainer fixed in the canine area is used within the upper or lower dentition and
is made individually from wire with a diameter of 0.03 inches. The tips of the arc are bent in
order to better adhere to the intraoral surface of the canines, followed by treatment to improve
the retention of the adhesive by light curing. The monofilament retainer for lower teeth is
one-piece, it is fast enough and clinically inexpensive to fix, it is easy to take individual care
of patients, and the number of successful cases (success refers to the absence of detachment
during the retention period), according to our data, was up to 90.6%. Each patient
immediately identifies a violation in the fixation of the retainer, since it stabilizes only in the
area of the canines. Being one of the most popular non-removable retainers, the
monofilament retainer is used in most cases in patients with a period of permanent bite with
mild to moderate degree of crowding of teeth before treatment within the lower dentition.
Flex-thin arch is widely used within the upper dentition of adolescents and adult
patients with orthodontic profile for the manufacture of a retainer with subsequent fixation on
four or six front teeth from the intraoral surface. The majority of authors associate the
fixation of the retaining structure only to the incisor group with greater stability and
minimization of peeling, the predictability of the results according to our data reaches 69.8%.
The attachment of canines to the retainer leads to a deterioration in the stability of the
structure and the amount of rebonding can reach up to 40.3% of the total number of fixations.
Removable retainers, regardless of the design solutions, have the main
disadvantage associated with the type of fixation, these devices are recommended for patients
with a high motivational status in the treatment process. Based on our work, more than a
quarter of individuals encountered difficulties in using these devices due to low discipline,
and in 18.2% of cases, a recurrence of orthodontic pathology was observed. According to the
generally accepted protocol, removable structures are worn continuously for 6 months, after
which they are used only during sleep for two years or more. In cases of so-called double or
combined retention, when removable and non-removable retainers are used simultaneously, it
is necessary to correctly manufacture the removable device in order to avoid a tight fit of the
removable retainer base to the permanent structure in order to avoid peeling.
Selective personalized retention refers to a type of retention of achieved results that
affects the part of the dentition where a local or general recurrence is more likely. Therefore,
it is worthwhile to use individually proposed retention methods in each specific case, which
is determined based on a diagnostic analysis of the initial clinical data, gender, presence of
parafunctions, patient's motivation for treatment, type of growth of the skull skeleton and the
patient's age. The choice of adhesive retainer design should be made at the final stages of
active therapy. Situational analysis of the initial and received data makes it possible to
localize the teeth or the area of the dentition most affected by relapse. The presence of
irreversible parafunctions, dysfunction of the external and internal muscles of the
maxillofacial region, gnathic or skeletal lesions of the maxillary system can lead to an
unsuccessful retention period. Particular caution should be exercised in cases of rotation and
crowding of teeth in the anterior and lateral areas of the dentition. After the end of the active
stage of treatment, the teeth that were in tortoanomaly should be included in the elements of
the retainer, including a group of premolars, or additionally fixed using vestibular wire
segmental retainers, in addition to the main retaining retainer.
The use of lightweight or shortened vestibular retainers was first proposed in 1992
by Axelsson and Zachrisson. They make it possible to achieve prolonged positive results in
complex clinical cases. The main aspects of the application of these structures are the
prevention of the reopening of the walls and the stabilization of the areas after closing the
gaps when removing premolars and molars, as well as the rotational and crowded position in
the lateral segments. In our work, it was proposed to replace wire with fiberglass for the
aesthetics of cognition, because according to data analysis, up to 82% of patients refuse this
type of retention due to visualization of metal elements during articulatory movements of the
lower jaw. The fixation strength and aesthetic perception of our proposed retainer in the
examined individuals were close to the maximum if they were short segments – two, three
teeth. In cases of bonding for four or more teeth, there were problems with the stability of the
structure. The percentage of unfixations and breakdowns during the use of short segments
was no more than 3.9% when wearing the structure for 12 to 18 months.
The cases of an individual and clinically sound approach to the process of retention
realization of the period can be clearly illustrated by the following clinical examples. Class
III Angle correction with orthodontic camouflage of gnatic anomaly, when the incisors of the
lower dentition are displaced intraorally in order to normalize the overlap in the anterior area.
In this case, the design of clinical choice is a flex retainer fixed to the six front teeth.
According to our data, this device reliably stabilizes this area of the dentition, unlike a thick
retainer fixed only to the canines. In cases of congenital hypodentia of the lateral incisors on
the upper jaw, when the gaps are consolidated and the canines are displaced to the place of
non-embedded teeth, an improved flex retainer with fixation on the premolars is used. In this
case, the design must be individually made, followed by preforming on a plaster model of the
jaw. Long-term retention in patients with transversal malocclusion is difficult, especially in
adult patients. When using classic removable retainers, we noted a gradual increase in the
narrowing of the upper dentition, which was associated with insufficient good discipline of
patients in the retention period, the number of relapses could reach 49.3% of the total number
of patients. In cases where long non-removable retainers were used, the positive retention
period was a higher percentage of 75.5%, the main problem with this design was the
unfixation on individual teeth. Therefore, it is advisable to introduce a modification of the
palatine flap as an adequate retention device for cross-bite.
In the course of our scientific and practical research, we have obtained data
indicating ambiguity in the approach to the implementation of the retention period in
orthodontic patients. The main problem of the current stage of orthodontics development is
the lack of a unified protocol for the management of the retention period. In our work, we
have shown a scientifically and clinically sound approach to the stabilization stage of
orthodontic treatment based on the personification of clinical material. By analyzing each
clinical case as an individual, it is possible to complete the treatment with a guaranteed
positive result. The classical protocol for the implementation of the retention period in the
orthodontics clinic is possible only in cases of mild to moderate pathology.

About the authors

Alina Rasulovna Rasulovna

Voronezh State Medical University named after N.N. Burdenko

Author for correspondence.
Email: alinakaitova2016@mail.ru
ORCID iD: 0009-0003-6100-4152

student

Russian Federation, 394036,Russia,Voronezh, Studencheskaya street, 10.

Mikhail Mikhailovich Tatarintsev

Voronezh State Medical University named after N.N. Burdenko

Email: tmmvolvo90@mail.ru

candidate of medical sciences, assistant of the department of pediatric dentistry with orthodontics 

Russian Federation, 394036,Russia,Voronezh, Studencheskaya street, 10.

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