Fixed therapy: The standard EDGEWISE
Introduction
One of the greatest advantages of orthodontics is the multitude of procedures available to the practitioner to correct dental malocclusion or skeletal dysmorphosis.
One of the possible classifications of these devices consists of distinguishing:
- Removable appliances that can be removed from the patient’s mouth,
- Fixed appliances, by definition fixed (sealed or glued) on the dental arches for the entire duration of the treatment.
Long called multi-bracket appliances, multi-attachment appliances , as they are more accurately called today, allow three-dimensional control of dental movement, in response to a force applied to the crown of the teeth.
Among them, the Edgewise system remains the most widespread, regardless of the orthodontic design used: standard Edgewise, Tweed-Merrifield, straight arch technique, lingual technique or segmented technique.
- History – Evolution
In 1728, in the first attempt to correct dental malocclusions, Pierre Fauchard used a simple wide arch on which the malpositioned teeth were ligated: the expansion arch , while already recommending in his treatise on teeth, the filing of dental tissues in the event of crowding.
At the end of the 19th century, technical and industrial progress in American companies allowed orthodontics to
take on a new lease of life. Some inventors that we still call today the
“fathers of modern orthodontics” will develop the foundations of today’s orthodontics.
Case used open or soldered tubes with gold rings, he created a new system
“Contouring” (1893) with two arches; vestibular and palatine.
At the same time, EHAngle , seeking above all to achieve tooth alignment, founded the first American school of orthodontics in 1887. He thus proposed different expansion systems to move and especially to orient teeth:
The “E-arch” (expansion arch) which only causes versions (2 D).
The “Pin-and-Tube” (a device with tenons and vertical tubes) is difficult to handle.
Then in 1913, the Ribbon-arch arrived : instead of attaching the metal arch to the tooth through an intermediary, it used metal bonds surrounding the teeth and having a system for attaching the wire. These were the first true orthodontic brackets.
Despite its great possibilities, this device also has its limits in 3D control and in particular in torque.
It was to meet these additional objectives that the Edgewise was developed.
Assisted by his students, Brodie and Charles Tweed, Angle finally presented the EDGEWISE appliance in 1925 , literally “on the small side”: it is a prefabricated system composed of metal brackets (also called consoles, locks or orthodontic attachments) equipped with a horizontal rectangular light, thus allowing perfect three-dimensional control of dental orientation and movement.
Charles H. Tweed followed his master’s precepts until the day when sufficient hindsight (6 years later) led him to recognize the merits of reducing dental equipment, it is little
satisfied with the aesthetic results (profiles that he found too convex) and noted the instability of the expansion treatments. He then performed extractions of the four first premolars.
Merrifield advances the diagnostic and strategic reasoning of Edgewise (choice of extractions according to malocclusion, control of the vertical direction), the technique is now called Edgewise of Tweed-Merrifield .
- Components of the Edgewise device
Edgewise is a removable-non-removable orthodontic appliance. It is not a treatment method but a mechanical system that allows controlled tooth movement.
The term Edgewise is explained by the fact that the rectangular wire is inserted into the bracket lumen by its narrower side. It includes:
- Fixed elements:
Braces : In the early days of Edgewise, all the teeth in the arch were fitted with braces, hence the name “multi-brace technique.” These braces were made on the teeth themselves using a metal band, then vestibular and lingual attachments were electrically welded to them .
Edgewise Tubes : Bonding allows the band to be removed and only the tube to be retained. This allows for the treatment of molars with low crown height. They are less traumatic for the periodontium because they facilitate hygiene. However, they are more prone to detachment.
Edgewise Bracket : The Edgewise bracket is a stainless steel block with a transverse groove in its middle, this groove is presented as a rectangular light slide of dimension .022 (height) * .028 (depth) knowing that 1 inch = 25.4 mm so we will have a light of 0.6 mm by 0.8 mm.
This bracket has no angulation or inclination (not informed). It is used for incisors, canines and premolars.
Accessory Attachments : Lingual buttons or hooks are widely used for correcting or controlling rotations or inversions of the bite. Eyelets can also be soldered at various locations on the ring.
- Removable elements:
The arches : which are the specific active elements of the Edgewise device, they are made from steel wire of different sections depending on the treatment phases.
We can find:
- Round or twisted arches
- Rectangular arches
- Hybrid bows
- Aesthetic arches
- Auxiliary forces:
The most commonly used auxiliaries in Edgewise technique are:
- Single or intra-arch force systems.
- Inter-arch force systems.
- Extraoral force systems.
- Principles of the Edgewise Technique:
In Edgewise, we seek above all to obtain the ideal alignment of all the teeth in the 3 planes of space:
Since the attachment is simple (without information), without angulation or inclination, how can these inclinations be obtained? This requires an adaptation of the arch to the various anatomical particularities of the dento-alveolar system, by making plications on the wire:
In the horizontal plane first-order deformations.
In the mesio-distal plane second-order deformations “angulation” or
“Tip” : These deformations can be divided into two categories:
- plications: tip-back, tip-forward, increase in the Curve of Spee.
- loops: which modify the flatness of the arc, and increase the length of the wire (omega loop, space closing loops, space opening loops, “U” loop, “sock” loop, quadrangle loop (box loop), etc.).
- There is another particular type of 2nd order bends called “artistic bends”, these are bends introduced in the finishing arches, they are of interest to the sector
incisor in order to give a slightly apico-divergent direction to the axes of the maxillary incisors.
In the vestibulo-lingual plane third-order deformation (torque)
- Processing phases in Edgewise technique:
It is obvious that each case will be treated according to the anomalies it presents.
However, in all Edgewise treatments we will find the same phases, the variations will be due to the direction of the movements and their amplitude.
These phases are as follows:
- Leveling phase: This is a flattening of the arch which is done at the beginning of any orthodontic therapy, it begins with the positioning and bonding of the attachments, then the correction of individual dental malpositions (rotations, version, crowding, etc.)
This will be done using a small diameter round wire of 0.12 or 0.14 inches. If the size is significant, the use of loops allows for correct alignment.
Its purpose is to allow the insertion of a rectangular arch.
- Anchorage preparation : This does not exist in all treatments. It depends on the anchorage needs revealed by the diagnostic analysis of the case and evaluated in the treatment plan. It aims to prepare the teeth in the lateral sectors, to withstand the stresses they undergo.
The objective is to place the teeth in a position of resistance to the forces applied to them, that is to say in a position of distoversion without mesializing their apices.
You can use TIM, FEB, J hooks.
- Mass tooth movement : Continuous rectangular archwires of increasing cross-section are used to initiate mass movements (canine retraction, incisor retraction). In this type of movement, the driving force is provided by numerous accessories chosen according to the anchorage and the amount of retraction. The initial optimal force is 100 g.
It can be issued by:
- Elastomeric chains,
- Compressed springs,
- OEM J-hooks
The objective of this phase is to obtain Cl 1 Canine and Molar.
- Finishing (ideal arches): Is done using rigid arches .021*.027 (full groove). This is an essential phase in the treatment which:
- Completes the accomplishment of the various processing objectives:
- Contributes to treatment stability;
- Determines the quality of the treatment. This is a delicate phase. Its objectives are:
- The coordination of arch shapes;
- Adjustment of 2nd and 3rd order curvatures;
- Overcorrection of the vertical and anteroposterior directions.
4- Restraint: This restraint can be removable :
- A Hawley plaque;
- A tooth positioner:
- A silicone gutter.
Or fixed : A retention bonded to the composite on the palatal surfaces of the teeth. It can be temporary (6 to 12 months) or permanent, uni- or bi-maxillary.
- Evolution towards the straight bow technique
As early as 1929, ANGLE already foresaw that this relationship between the archwire and the bracket could be different and anticipated the advantages of an archwire free of deformations; he wrote: ” Another excellent way to achieve disto-version of the posterior teeth is to change the position of the brackets on the bands instead of making vertical bends on the archwire. This allows the use of the archwire in its simplest form, bends are avoided which, obviously, has advantages .”
The transfer of information to the attachment allows:
- Facilitate the implementation of multi-attachment techniques:
- Ensure consistency of information from one arc to another;
- Allow the use of non-shapeable arches while ensuring early control of dental inclinations;
- Optimize dental sliding movements.
Conclusion
Edgewise remains the technique that offers the most rigorous mechanical possibilities .
Since its invention, it has given rise to various methods. The most elaborate is the Tweed method, but many other methods using continuous or segmented arches use the properties of this technique, namely the original embedding system: rectangular wire – calibrated attachment.
Angle told his students, ” All you can do to correct teeth is push them, pull them, twist them. I gave you the braces, for God’s sake, use them! “
Bibliography
- AnneMarie Duhart. EtienneBardinet. Dominique Bequain. François Darque Danielle Dorignac. Orthodontic biomechanics and the notion of “light force” EMC (Editions Scientifiques et Médicales Elsevier SAS, Paris,), Odontology/Dentofacial Orthopedics 23- 490-D-10.1998.
- ATTIA. Y. Edgewise EMC (Editions Scientifiques et Médicales Elsevier SAS, Paris), Odontology/Dentofacial Orthopedics 23-490-D10.1985.
- Bassigny F. Dentofacial orthopedics manual. Paris: Masson, 1991, (p 07-15).
- Boileau MJ. Orthodontics for children and young adults. Volume 2, Volume 2,. 2012.
- Michel Château: Clinic, Diagnosis, Treatment, Stabilization. Cdp Edition. 1993.
- Michel LANGLADE. Orthodontic Therapy. MALOINE SA PUBLISHER. 1986. Quintessence Internationale 2003.
Fixed therapy: The standard EDGEWISE
Untreated cavities can cause painful abscesses.
Untreated cavities can cause painful abscesses.
Dental veneers camouflage imperfections such as stains or spaces.
Misaligned teeth can cause digestive problems.
Dental implants restore chewing function and smile aesthetics.
Fluoride mouthwashes strengthen enamel and prevent cavities.
Decayed baby teeth can affect the health of permanent teeth.
A soft-bristled toothbrush protects enamel and sensitive gums.