In 1925, Edward Angle introduced the Edgewise braces system and suggested a 0.022-inch x 0.028-inch arch opening size, which allowed for better control over crown and root position with available precious metal wires. at that time.1 With technological advances, stainless steel began to use alloys Steel in orthodontics, which allows manufacturing thinner wires of the same hardness as gold arc wires at a lower cost 2,3 This allowed to reduce the bow hole size to 0.018 inch. However, this did not preclude the continued use of 0.022-inch arc nozzles in clinical practice.
Certain biomechanical advantages and disadvantages of using 0.018 inch and 0.022 inch arc holes have been suggested. It is of primary importance that the wire fills the arch opening to express the angle of bend and inclination. A 0.018-inch arch hole can be filled at the beginning of treatment to improve torque control for the front teeth.5 Additionally, the smaller, more flexible archwires used with the 0.018-inch aperture are more easily handled by the orthodontist. On the other hand, the 0.022-inch rack opening makes it easier to insert the arc cables on the first visit, provides more size and wiring configuration options, gives the cables greater freedom of movement during the initial alignment stage, thus obtaining 7.8 lighter forces later in the treatment, the wiring The larger diameter arch used in the 0.022 inch arch hole is more rigid and helps to control the teeth in the vertical dimension during the mechanics of closing and retraction by empty.
Preferences for each incision size vary around the world, and the choice is often experimental, based on the recommendations of a particular dental school. In many European countries, 0.018-inch arch openings are used more frequently, while in the United States, most orthodontists work with 0.022-inch openings 3.5 There is little evidence in the literature to show the advantages of one system over another; Therefore, orthodontists make this clinical decision with little scientific guidance.
Consequently, the main objective of this systematic review was to determine whether the use of 0.018-inch or 0.022-inch arch openings influences the duration of treatment, the efficiency of vacuum closure, the efficiency of alignment, the quality of the orthodontic finish. , the level of discomfort and the level of root resorption.
materials and methods
Protocol and registration
This systematic review is registered with PROSPERO under the protocol CRD42015015916 and is available at http://www.crd.york.ac.uk/PROSPERO/register_new_review.asp?RecordID=15916&UserID=9696.
This systematic review used the PICO (Population Intervention-Comparative Results) strategy for the research carried out. Prospective and retrospective clinical studies were selected with patients whose fixed orthosis used 0.018 inch or 0.022 inch arch openings. As a result, the results of eligible studies should have evaluated the quality of orthodontic finish, duration of treatment, efficiency of alignment, pain experience, efficiency of orthodontic space closure, and / or root resorption. Laboratory reports, editorials, clinical cases, and studies that did not compare 0.018-inch and 0.022-inch arch openings were not included.
Several electronic databases were searched (PubMed, Medline, Bireme, Scopus, Web of Science, Google Scholar, and Open Gray). We also handsearched using the references of the selected articles.
No language or date restrictions were applied to the searches and the following terms were used, which were adapted to each grammar rule: “fixed orthodontic device”, “fixed device”, “orthodontic treatment”, “orthodontic patient” or “Orthodontic brackets” or “orthodontic device design” or “orthodontic device” and “abutment size” or “abutment opening” or “abutment dimension” or “opening dimension” or “abutment height” or “Arch opening size” or “Opening size or” Aperture support system “and opening of” 0.018 inches “or” .018 inches “or” 0.018 inches “and” 0.022 inches “or” .022 inches ” or “0.022 inches”. In addition, the authors have included MeSH synonyms, related terms, and free terms. Searches were run through May 20, 2017.