Canine retraction: A systematic review of different methods used

Abstract

Canine retraction is a very important step in treatment of patients with crowding, or first premolar extraction cases. In severe crowding cases until, the canines have been distilized to relive the crowding, space to correctly align the incisors will not be available. Correct positioning of the canines after retraction is of great importance for the function, stability, and esthetics. The aim of this systematic review was to examine, in an evidence-based way, which kinds of canine retraction methods/techniques are most effective and which have the least side effects. A literature survey was performed by applying the Medline Database (Entrez PubMed) and Science Direct database covering the period from 1985 to 2014, to find out efficient ways to accomplish canine retraction. Randomized controlled trials (RCTs), prospective and retrospective controlled studies, and clinical trials were included. Two reviewers selected and extracted the data independently and assessed the quality of the retrieved studies. The search strategy resulted in 324 articles, of which 22 met the inclusion criteria. Due to the vast heterogeneity in study methods, the scientific evidence was too weak to evaluate retraction efficiency during space closure. The data so far reviewed proved that elastomeric power chains, elastic threads, magnets, NiTi coil springs, corticotomies, distraction osteogenesis, and laser therapy, all are able to provide optimum rate of tooth movements. All the methods were nearly similar to each other for retraction of canines Most of the techniques lead to anchorage loss in various amounts depending on the methods used. Most of the studies had serious problems with small sample size, confounding factors, lack of method error analysis, and no blinding in measurements. To obtain reliable scientific evidence, controlled RCT's with sufficient sample sizes are needed to determine which method/technique is the most effective in the respective retraction situation. Further studies should also consider patient acceptance and cost analysis as well as implants and minor surgeries for canine retraction.

Examination of postextraction space closure speed using elastic chains and NiTi closed coil springs

“…Comparing the rate of post-extraction spaces closure in observed period, our study found the value greater than 0.84 mm using NiTi closed coil springs. There are numerous studies that compared these two methods and confirmed these results [22,28,29]. In addition to these, Dixon et al also compared active ligatures ie.…”

“…Although there are numerous ways to close post-extraction spaces, many authors recommend sliding mechanisms as very effective method using fixed orthodontic appliances [22]. Minimal bending of the wire, quick and simple reactivation and time saving are the advantages that make the sliding mechanism method of choice for most orthodontists [11].…”

“…Iako postoje brojni načini za zatvaranje postekstrakcionih prostora, mnogi autori preporučuju klizne mehanizme kao veoma efikasnu metodu u okviru terapije fiksnim ortodontskim aparatima [22]. Minimalno savijanje žice, brza i jednostavna reaktivacija i ušteda vremena su prednosti zbog kojih klizni mehanizam predstavljaju metodu izbora kod većine ortodonata [11].…”

“…Prilikom poređenja brzine zatvaranja postekstrakcionih prostora u posmatranom periodu, ovim istraživanjem je ustanovljeno da je primenom NiTi zatvorenih spiralnih opruga vrednost veća za 0,84 mm u odnosu na elastične lance. Postoji veliki broj istraživanja u kojima su se poredile ove dve metode i koja potvrđuju ove rezultate [22,28,29]. Dixon i saradnici, pored navedenih, poredili su i aktivne ligature, odnosno klizni mehanizam koji se sastoji od čelične ligature i elastičnog prstena.…”

Comparing the rate of retraction in canines in males and females

“…It was to provide a friction-free environment which would allow better sliding mechanics and thereby reduce the treatment time. (Kulshrestha et al, 2015) Recently came the evolution of Synergy brackets. Synergy bracket is one of the commercially available brackets that is most versatile and active.…”