A comprehensive review on loops in orthodontics

Extraction therapies are commonly done in patients with protrusion and/or crowding which demands a thorough understanding of biomechanics. Two basic types of space closing mechanics are friction/sliding and frictionless/loop mechanics. In the former, the wire and position of the bracket are important factors in tooth movement but the simplicity of friction mechanics is offset by the binding between bracket and archwire and may be associated with undesirable side effects such as uncontrolled tipping and deep bite. In frictionless mechanics, specially designed springs are used which provides the required moment to force ratio (M/F ratio) in three dimensions and they are more predictable and versatile. An electronic literature search was conducted via google scholar, PubMed, and dental associations’ of different countries’ website using the key word “Loops” and “Frictionless mechanics.Different configuration of loops have been used in orthodontic treatment and a comprehensive review of types of loops commonly used in retraction has been highlighted in this article.: Provide appropriate messages of about 35-50 words to be printed in centre box:In frictionless mechanics, specially designed springs are used which provides the required moment to force ratio in three dimensions and they are more predictable and versatile. Different configuration of loops have been used and a comprehensive review of types of loops commonly used in retraction has been highlighted in this article.