A. INDIRECT BONDING
Indirect bonding of orthodontic brackets was first introduced by Dr. in 1973. Silvermann and Dr. It gained popularity as a result of Cohen's work. However, on bonding, Dr. A survey conducted by Gorelick showed that only 17% of orthodontists preferred indirect bonding. Again in 1978, Zachirson stated that indirect bonding had a serious failure rate in adhesion compared to direct bonding. However, in more recent studies, as stated by Aguirre et al., there are not that big of a difference between indirect bonding and direct bonding in terms of adhesion strength.
Although indirect bonding of labial (front surface of the teeth) brackets is completely optional, indirect bonding of lingual brackets is completely optional. It is a necessity, if not an absolute must, that it be adhered as such. Because;
a. Irregular lingual tooth morphology requires special shaping of the lingual bracket base
at this stage.
b. The wide variation in lingual tooth morphology requires special measurements that require selection of bracket base thickness and
torque according to the tooth.
c. The practitioner's much less familiarity with lingual tooth morphology makes it very difficult to estimate bracket height and angles in the clinic.
d. It is very difficult to obtain direct vision for bonding to lingual surfaces.
e. Complete accuracy is required in bracket positioning, because various bendings made to compensate for small errors, as is sometimes done in the labial
technique, are both much more difficult and time consuming in the lingual
arch wire.
f. The variation in lingual surface morphology, both between different patients and within the same patient, is much larger than that encountered in labial anatomy and is often clinically intolerable. This situation is a big
problem in bracket positioning and adhesion.
g. When height measurements are applied as in direct labial bonding, inaccurate
lingual height data will occur.
B. CASE PREPARATION
First of all, patients It should be brought to a healthy state in terms of odontology (gums and surrounding tissues). Patients should be given prophylaxis and hygiene training and be sure of the current state and sustainability of periodontal health. Anatomical variations that can be encountered from time to time, especially in the upper canine teeth, prevent correct bracket placement and cause bracket torque values to change. These structures should be reduced before measurement and approximated to their normal dimensions.
Again, teeth with excessively concave-shaped lingual surfaces and spoon-shaped incisors, which are frequently seen in Eastern races, should be filled with composite. Frequently, the gingival 1 / 3 lingual crown part is shaped to form mesial and distal marginal ridges.
In the presence of metal or porcelain prostheses on the tooth to be treated orthodontically, plastic should be replaced with acrylic ones before treatment. When making these teeth, care should be taken to ensure that they are compatible with the lingual anatomy in terms of thickness, height and morphology.
Dental morphological anomalies, such as dens in dente or dens invaginatus, which can be seen especially in the upper lateral incisors, should be restored with composite.
Amalgam restorations should be removed if possible. , teeth should be restored with composite.
Applications such as separation, extractions, removable devices and stripping that may cause tooth movement should be done after the lingual brackets are placed. Because performing these procedures after the measurement will jeopardize complete harmony.
In cases that have previously used removable devices or received any other type of orthodontic treatment, stabilization must be ensured between the measurement and the set-up phase.
In addition, the plaster cast should be cast immediately after the measurements are taken, and for maximum adaptation, the time between the measurement and the set-up phase and its application to the patient should be kept as short as possible without extending it.
C. APPLICABLE LABORATORY PROCEDURES
First, the correct bracket position and height must be determined. At this stage, the necessary alignment bends often needed between the canines and premolars are also determined.
After the bracket location is precisely marked on the model, the brackets are placed. TARGTM (Torque/Angulation Reference G) has been used for many years today. uide) and CLASS (Custom Lingual Appliance Set-up Service) techniques, there are techniques such as Hiro system and Ray Set® that can detect the bracket position with high consistency.
1. TARGTM(Torque/Angulation Reference Guide);
In the original TARGTM method, the TARGTM machine developed by Ormco in 1984 is used. In this way, set-up can be done with much greater ease and accuracy. The torque tips of the machine are used to determine the horizontal planes of all teeth. In this way, brackets can be glued at the distance determined for each tooth from the chewing surface. However, in the original machine, it was not possible to measure the anteroposterior thicknesses, which may be different for each tooth, and thus to determine the in-out relationships in advance. For this purpose, in 1987, Didier Fillion added an electronic device to the TARGTM machine that could also measure the anteroposterior thicknesses of the teeth. . He could also create individual arc form tables with the computer program called DALI (Dessin Arc Linguale Informatisé), developed by the same practitioner.
2. CLASS (Custom Lingual Appliance Set-up Service);
It is a technique developed for bracket positioning with greater consistency than the TARGTM method. The set-up model prepared from the per-treatment model is used to ensure exact bracket fit. However, the difficulty of transferring from the set-up model to the malocclusion model, complex laboratory procedures and cost are the disadvantages of this technique.
3. HYRO SYSTEM;
This system aims to make laboratory procedures as easy as possible, without using expensive equipment or electronic devices, and to ensure that the treatment is continued with the straight-wire technique.
Based on the prepared set-up model. An ideal arc is bent from appropriately squared wire. Afterwards, the bracket positioned appropriately in the model is adapted with the arch wire, and single rigid carriers are shaped for each tooth.
4. RAY SET®;
Ray Set® is the final point of indirect bonding application today. With correct use, it completely eliminates subjectivity and individual errors, evaluates each tooth as a separate unit isolated from the arch it is in, and creates a three-dimensional view. It has the ability to detect first, second and third order values with 100% accuracy with its trolling system.
D. CORRECT BRACKET POSITION
In lingual orthodontics, a solid infrastructure is required to achieve the desired results. Therefore, bracket positioning is of great importance. With indirect bonding, care should be taken in positioning the tooth according to its form and shape, taking into account its inclination, in-out and torque values.
Predetermined bracket placement facilitates the treatment. Many lingual brackets today are manufactured to accommodate angles, torque and in-out values in their internal design. Again, the bracket base is designed to adapt to the contours of an average lingual surface, which can be described as ideal. However, making the bracket base from a softer, malleable metal compared to the other parts of the bracket allows the bracket base to be shaped in the laboratory stage to be as compatible as possible with the lingual surface contact.
Although pre-shaped brackets facilitate the treatment to a great extent, they still Factors such as size, lingual contour, very large variations in marginal edge anatomy, inconsistencies in tooth form, shape of restorations and lingual surface slope require caution when using these brackets. For example, a small difference in the distance of the bracket from the incisal edge may affect the vertical position of the tooth. and thus, it will affect the in-out relationships.
If there are teeth placed at the same height but with different thicknesses in the anteroposterior direction, the distances of the brackets to the front surface of the tooth will be different and this will cause irregularity in the anteroposterior direction.
Even though they are placed at the same height in the vertical direction, the incisal edges will be positioned differently and irregularly in teeth with different lingual face inclinations. Therefore, in these types of teeth, brackets should be positioned differently, proportional to the inclination from the cutting edge.
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