Brackets
Brackets ( Engl. Brackets) are orthodontics common fasteners with fixed appliances (. Cf braces ). They are bonded to the surface of the tooth using special adhesive techniques and thus form a starting point for moving teeth with fixed appliances. A characteristic of a bracket is the device for holding arches, the so-called lock or slot. This is a horizontally running slot. This is limited at the top and bottom by the tips of a wing, which are used to fasten the arch with the help of ligatures . The standard bracket has two wings and is therefore referred to as a twin bracket. Occasionally, brackets with only one wing are used; these are referred to as single brackets. According to the shape of the lock, brackets can be differentiated into Edgewise brackets (attachment of the arch with ligatures), light wire brackets (attachment of the arch with pins) and self-ligating brackets (the bracket itself holds the arch without ligature). The lock has a quadrangular cross-section, which is either the dimensions (H × D in inches has) 0.018 "x 0.025" or 0.022 "x 0.028". In technical terminology, one speaks of the “zero-eighteenth” and “zero-twenty-two” system. Both systems are not compatible with each other. In addition, brackets can be differentiated according to where they are attached to the tooth. If they are attached to the outside of the cheek , they are called buccal brackets . If they are on the inner surface, towards the tongue , they are called lingual brackets .
The standard bracket is made of stainless steel . Both the metallic color as well as in the alloy contained nickel units led to the development of other materials. Today brackets are offered in addition to stainless steel made of gold , ceramic , composite and titanium . Due to the higher purchase price of these brackets, the additional costs usually have to be borne by the patient.
An important property that can be decisive for the choice of bracket and arch material is friction . In many treatment concepts, the bracket should slide over the arch ( sliding mechanics ). Both the combination of bracket and arch material and the type of ligature used can increase or decrease the friction.
If the adhesive technique is not used properly or oral hygiene is poor while the brackets are sticking to the teeth, permanent decalcification stains can remain on the tooth surfaces.
History and Development
The first fixed appliances for tooth regulation were mentioned by Pierre Fauchard in 1728 (Le Chirurgien Dentiste ou traite des dents). The tooth to be positioned and the neighboring teeth were fixed to a gold band with wire elements or silk threads. This band device has been further developed with various additions (wooden wedges, caps, eyes, rings).
The next big step was not taken until 1916, when Edward H. Angle developed the Ribbon Arch appliance. This enabled the three-dimensional regulation of teeth for the first time. The apparatus thus formed the starting point for all other bracket developments.
Another important intermediate step was the Edgewise apparatus also developed by Angle. With this, the tooth movement could be significantly improved by changing the arch dimension and the angulation control. This is also the starting point for the development of further brackets with a wide variety of shapes, sizes, slot dimensions, slot numbers, bracket base contours and locking mechanisms.
literature
- ^ Lexicon dentistry, dental technology, Urban & Fischer, p. 111, ISBN 3-437-05060-5
- ^ Kahl-Nieke: Introduction to orthodontics , 2nd edition, Urban & Fischer, p. 205, ISBN 3-437-05420-1
- ↑ L. Currie, TJ Gillgrass: Advances in Fixed Appliance Orthodontics . In: Dent Update . 2004 Oct; 31 (8): 463-4, 466-8, 471. PMID 15554051
- ^ RP Kusy, JQ Whitley: Friction Between Different Wire-Bracket Configurations and Materials . In: Semin Orthod . 1997 Sep; 3 (3): 166-77. PMID 9573878
- ↑ Ludwig et al .: Self-ligating brackets. Georg Thieme Verlag, New York Stuttgart 2009
