Effectiveness of orthodontic temporary anchorage devices in canine retraction and anchorage preservation during the two-step technique: a systematic review and meta-analysis

Abstract

Background Temporary anchorage devices have been used for decades in orthodontic practice for many applications. The aim of this systematic review was to assess the effectiveness of orthodontic temporary anchorage devices in canine retraction during the two-step technique. Methods A search was systematically performed for articles published prior to June 30, 2019 in five electronic databases (PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Scopus). The risk of bias was assessed using the Cochrane risk of bias tool for randomized controlled trials (RCTs) and the risk of bias in nonrandomized studies of interventions (ROBINS-I) tool for controlled clinical trials (CCTs). The Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach was used for the quality assessment. Data concerning the mean difference in mesial molar movement and extent of canine retraction were extracted for statistical analysis. The mean differences and 95% confidence intervals were analyzed for continuous data. A meta-analysis with a random-effects model for comparable outcomes was carried out. Results Three RCTs and five CCTs were finally included. Meta-analysis showed a significant increase not only in anchorage preservation in the implant anchorage group in both the maxilla (1.56 mm, 95% CI: 1.14 to 1.98, P < 0.00001) and the mandible (1.62 mm, 95% CI: 1.24 to 2.01, P < 0.00001) but also in canine retraction in the implant anchorage group in both the maxilla (0.43 mm, 95% CI: 0.16 to 0.69, P = 0.001) and the mandible (0.26 mm, 95% CI: 0.02 to 0.49, P = 0.03). Conclusions There is very low-quality evidence showing that implant anchorage is more efficient than conventional anchorage during canine retraction. Additional high-quality studies are needed.

Which anchorage device is the best during retraction of anterior teeth? An overview of systematic reviews

“…28 , 29 Miniscrews were also more effective in preserving the anchorage than were conventional anchorage methods in the two-step retraction technique. 32 …”

“…There was greater but non-statistically significant distal molar tipping with miniscrews when compared to conventional anchorage methods. 23 On the other hand, another meta-analysis 32 reported (from one study) that mesial tipping of maxillary and mandibular molars was significantly greater with the conventional anchorage methods than with miniscrews by 2.15˚ and 2.5˚, respectively.…”

“…Two-step retraction technique : anchorage preservation was greater with miniscrews than with the conventional anchorage methods both in the maxilla (mean difference −1.56 mm, 95% CI: −1.98 to −1.14 mm) and the mandible (mean difference −1.62 mm, 95% CI: −2.01 to −1.24 mm) with an overall greater effect of the direct anchorage method. 32 …”

“…Distal tipping of the canines was also greater in the miniscrew group than in the conventional anchorage group in both arches by about 3˚, however this difference was not statistically significant. 32 …”

“…Several systematic reviews 8 , 20 - 32 have compared the clinical effectiveness of different types of anchorage devices in terms of the amount of anchorage loss; sagittal and vertical dental, skeletal, and soft tissue changes; duration of treatment; quality of treatment; patient perception; and adverse effects. However, to date, researchers have not provided a robust and clear answer to the following question: which anchorage method is the best during retraction of anterior teeth according to these different treatment outcomes?…”