The Damon system of orthodontics is one of many fixed, passive, self-ligating methods of correcting

malocclusion In orthodontics, a malocclusion is a misalignment or incorrect relation between the teeth of the upper and lower dental arches when they approach each other as the jaws close. The English-language term dates from 1864; Edward Angle (1855-19 ...

s. Passive self-ligating systems use brackets that do not require elastic

o-ring An O-ring, also known as a packing or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a round cross-section, designed to be seated in a groove and compressed during assembly between two or more par ...

s to hold the wires in place. By not using the elastic o-rings, it is said that the wires freely slide through the slots without friction. However, this may not be correct as it allows more rotation or tipping of teeth (and therefore some potential loss of precision of movement) before the bracket edges contact the wire, resulting in friction. It is believed that not using o-rings results in better

oral hygiene Oral hygiene is the practice of keeping one's mouth clean and free of disease and other problems (e.g. bad breath) by regular brushing of the teeth (dental hygiene) and cleaning between the teeth. It is important that oral hygiene be carried out ...

but the research is equivocal, with findings both for and against the theory. To hold the wires in place, the Damon System uses small sliding doors. The addition of 'stops' on the wires helps prevent the wire from becoming displaced from its intended location.

Procedure

In passive self-ligating braces, orthodontic treatment begins with very light wires 0.014 inch in diameter that are made of an

alloy An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductilit ...

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow ...

, and

titanium Titanium is a chemical element with the Symbol (chemistry), symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resista ...

(CuNiTi) and have a non-anatomical shape because they are wider than the natural arch. Successively thicker wires are placed as the arches round out and as the teeth level. The next-larger wire is used when it may be passively placed in the brackets. The use of initial light wires and the passive placement of subsequent heavier wires made of stainless steel and/or a TMA alloy may reduce the pressure exerted on the periodontal ligaments. This may compromise the

blood flow Hemodynamics or haemodynamics are the dynamics of blood flow. The circulatory system is controlled by homeostatic mechanisms of autoregulation, just as hydraulic circuits are controlled by control systems. The hemodynamic response continuously m ...

and trigger a nonphysiologic osteoclastic/osteoblastic activity. However, there is no evidence to support this claim of less force. Tooth movement has been claimed to occur more rapidly and more comfortably by many doctors using passive self-ligating braces. However numerous randomised clinical trials (RCT's) (e.g.), have been conducted on these brackets and the summary systematic reviews of these have found no difference in the rate of tooth movement or overall treatment time between conventional brackets and Damon brackets,.

References

{{reflist Orthodontics