Background
Methods
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Study design: Prospective randomized and controlled clinical trial. The exclusion criteria were as follows: review articles, animal studies, case reports, lack of a control group, partial canine retraction and en masse retraction of the anterior teeth, and space closure not performed with sliding mechanics.
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Population: Orthodontic patients requiring extraction of the bilateral first premolars and retraction of the canines during the two-step technique.
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Intervention: Miniscrew implants for anchorage preservation during the first phase of the two-step retraction technique.
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Comparison: Conventional anchorage methods for anchorage preservation during the first phase of the two-step retraction technique.
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Outcomes: The primary outcomes were mesial movement of the first molars (anchorage loss) and the extent of canine retraction in both the maxilla and mandible. The secondary outcomes were tipping of the canines and molars and vertical molar movement. All the outcomes were measured in two cephalometric radiographs; one was taken before canine retraction, and the other one was taken after the completion of canine retraction.
Protocol registration
Search strategy and study selection
Data extraction
Risk of bias in individual studies and quality of evidence
Dealing with zero values
Data synthesis
Results
Study selection
Study characteristics
Reference | Character of patients | Study type (RCT/CCT)/design | Conventional anchorage | Location of implant | Number of implants | Mode of implant anchorage | Success rate of TAD (%) | Method of measuring tooth movement | Archwire/Force system |
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Davis et al., 2018 [14] | 10(mean age:17.3 years) 6F/4M (10 implant) | RCT/ split-mouth | DA | Placed between the roots of the second premolar and the first molar on the right buccal side (eight patients both in maxillary and in mandible; two patients only in maxillary) | 2/1 | Direct | 100% | cephalometric | 19 × 25 SS/ NiTi-closed coil spring |
Sharma et al., 2012 [32] | 30(mean age:17.4 years) 20F/10M (15 implant;15 non-implant) | RCT/ parallel | TPA | Placed between the roots of maxillary second premolar and first molar on both buccal sides | 2 | Direct | 100% | cephalometric | 19 × 25 SS/ Nitinol closed coil springs |
Gökçe et al., 2012 [33] | 18(mean age:16.7 years) 10F/8M (9 implant;9 non-implant) | RCT/ parallel | TPA (Max) Lb (Man) | Placed between the roots of the first molar and second premolar in all the four quadrants on the buccal sides | 4 | Direct | 100% | cephalometric | NR/ NiTi-closed coil spring |
Borsos et al., 2012 [15] | 30(mean age:14.22 years) 17F/13M (15 implant;15 non-implant) | CCT/ parallel | TPA | Midpalatal | 1 | Indirect | 100% | cephalometric | 16 × 22 SS /NiTi-closed coil spring |
Thiruvenkatachari, 2006 [38] | 10(mean age:19.6 years) 7F/3M (10 implant) | CCT/ split-mouth | DA | Placed between the roots of the second premolar and the first molar on one buccal side (eight patients both in maxillary and in mandible; two patients only in maxillary) | 2/1 | Direct | 100% | cephalometric | NR/Nickel-titanium closed-coil springs |
Hedayati et al., 2007 [37] | 19(Implant group:17.4 years DA group:18.2 years) (9 implant,10 non-implant) | CCT/ parallel | DA | Inserted in the midline of the palate approximately parallel to the upper second molars,in maxillary and in the buccal area of the second and third lower molars on two sides in mandible. | 3 | Indirect (Max) Direct (Man) | 81.48% | cephalometric | NR/NiTi pull coil springs |
Thiruvenkatachari et al., 2008 [39] | 12(mean age:19.7 years) 8F/4M (12 implant) | CCT/ split-mouth | DA | Positioned between the roots of the second premolar and the first molar on one buccal side. (ten patients both in maxillary and in mandible; two patients only in maxillary) | 2/1 | Direct | 100% | cephalometric | 16 × 22 SS/ Nickel-titanium closed-coilsprings |
Chaudhary et al., 2014 [40] | 17 (17 implant) | CCT/ split-mouth | DA | Placed between the roots of the second premolar and the first molar on right buccal side both in maxillary and in mandible. | 2 | Direct | 100% | CBCT generated 2D cephalometric | 17 × 25 SS/NiTi closed coil spring |
Reference | Diameter / length (mm) of TISAD† | Magnitude of force(g) | Mesial molar movement (mm) † | Tipping of molar(°) | Vertical change of molar (mm) † | Canine retraction (mm) † | Tipping of canine(°) | Treatment time (mon) | ||||||
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TISAD (Max/Man) | CA (Max/Man) | TISAD (Max/Man) | CA (Max)/(Man) | TISAD (Max/Man) | CA (Max/Man) | TISAD (Max/Man) | CA (Max/Man) | TISAD (Max)/(Man) | CA (Max) /(Man) | TISAD | CA | |||
RCTS | ||||||||||||||
Davis et al., 2018 [14] | 1.3/8 | 100 | 0.1/0.0625 | 1.3/1.3125 | 0.30/0.19 | 2.45/2.69 | NR/NR | NR/NR | −4.4/−3.5 | −4.2/−3.5 | NR/NR | NR/NR | 4–7 | 4–7 |
Sharma et al., 2012 [32] | 1.2/8 | 150 | 0/NR | 2.48/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR | NR |
Gökçe et al., 2012 [33] | 1.6/8 | 100 g | 0/0 | 1.7/1.8 | NR/NR | NR/NR | NR/NR | NR/NR | − 4.38/− 4.09 | − 3.71/− 3.62 | NR/NR | NR/NR | NR | NR |
CCTS | ||||||||||||||
Borsos et al., 2012 [15] | 4.1/4 | 150(cN) | 1.57/NR | 1.48/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | 9.11 ± 5.70 | 7.08 ± 4.44 |
Thiruvenkatachari et al., 2006 [38] | 1.3/9 | 100 | 0/0 | 1.6/1.7 | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | 4–6 | 4–6 |
Hedayati et al., 2007 [37] | 2/9(Max) 11(Man) | 180 | 0.58/−0.18 | 2.5/2.55 | NR/NR | NR/NR | −0.330/0 | − 0.950/−1.020 | NR/NR | NR/NR | NR/NR | NR/NR | 5.4 (4–6.5) | 5.4 (4–6.5) |
Thiruvenkatachari et al., 2008 [39] | 1.2/9 | 100 | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | NR/NR | − 4.2917/− 4.1 | −3.7917/− 3.75 | NR/NR | NR/NR | 4–6 | 4–6 |
Chaudhary et al., 2014 [40] | 1.2/8 | 120–150 | −0.41/− 0.05 | 1.31/1.03 | NR/NR | NR/NR | NR/NR | NR/NR | −6.75/− 4.83 | −6.03/−5.03 | −9.51/−7.88 | − 6.51/− 4.34 | 6–8 | 6–8 |
Risk of bias assessment
Authors (years of publication) | Bias due to confounding | Bias in selection of participants into the study | Bias in classification of interventions | Bias due to deviations from intended interventions | Bias due to missing data | Bias in measurement of outcomes | Bias in selection of the reported result | Overall bias |
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Thiruvenkatachari et al., 2006 [38] | Low | Moderate | Low | Low | Low | Serious | Low | Serious |
Hedayati et al., 2007 [37] | Low | Moderate | Low | Low | Low | No information | Low | Moderate |
Thiruvenkatachari et al., 2008 [39] | Low | Moderate | Low | Low | Low | Serious | Low | Serious |
Borsos et al.,2012 [15] | Low | Low | Low | Low | Low | Low | Low | Low |
Chaudhary et al., 2014 [40] | Low | Low | Low | Low | Low | Serious | Low | Serious |
Primary outcome measures
Mesial molar movement (anchorage loss)
Distal canine movement
Secondary outcome measures
Discussion
Summary of the evidence
Outcomes (study design) | No of Participants (studies) | Quality of evidence (GRADE) | Anticipated absolute effects (95% CI) |
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Maxillary anchorage loss (randomised trials) | 116 (3 studies) | ⊕⊝⊝⊝ VERY LOW1 due to risk of bias, inconsistency, imprecision | 1.8 lower (2.63 to 0.96 lower) |
Mandibular anchorage loss (randomised trials) | 52 (2 studies) | ⊕⊝⊝⊝ VERY LOW1 due to risk of bias, inconsistency, imprecision | 1.48 lower (2.02 to 0.95 lower) |
Maxillary anchorage loss (observational studies) | 152 (4 studies) | ⊕⊝⊝⊝ VERY LOW1 due to risk of bias, inconsistency, imprecision | 1.39 lower (1.89 to 0.88 lower) |
Mandibular anchorage loss (observational studies) | 88 (3 studies) | ⊕⊝⊝⊝ VERY LOW1 due to risk of bias, inconsistency, imprecision | 1.76 lower (2.41 to 1.1 lower) |
Maxillary canine retraction (randomised trials) | 56 (2 studies) | ⊕⊝⊝⊝ VERY LOW1 due to risk of bias, imprecision | 0.31 lower (0.72 lower to 0.09 higher) |
Mandibular canine retraction (randomised trials) | 52 (2 studies) | ⊕⊝⊝⊝ VERY LOW1 due to risk of bias, inconsistency, imprecision | 0.14 lower (0.28 lower to 0.57 higher) |
Maxillary canine retraction (observational studies) | 58 (2 studies) | ⊕⊝⊝⊝ VERY LOW1 due to risk of bias, imprecision | 0.51 lower (0.86 to 0.16 lower) |
Mandibular canine retraction (observational studies) | 54 (2 studies) | ⊕⊝⊝⊝ VERY LOW1 due to risk of bias, inconsistency, imprecision | 0.31 lower (0.6 to 0.03 lower) |