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| Title |
Temporary Anchorage Devices Are More Effective in Preserving Orthodontic Anchorage Than Conventional Anchorage Devices For Treating Class I or II Malocclusion With Dentoalveolar Protrusion |
| Clinical Question |
In patients with class I or II malocclusion with dentoalveolar protrusion requiring extraction of maxillary premolars and en-masse retraction of anterior teeth, do temporary anchorage devices (TADs) reduce anchorage loss by minimizing mesial movement of maxillary first molars more compared to conventional anchorage devices? |
| Clinical Bottom Line |
For patients with malocclusion requiring extraction of maxillary premolars and en-masse retraction of anterior teeth, treatment with TADs is more effective than treatment with conventional anchorage devices in reducing anchorage loss. This is supported by two systematic reviews of moderate quality and composed of randomized control trials (RCTs), prospective controlled trials, and retrospective studies that show treatment with TADs outperformed treatment with conventional anchorage devices in reducing anchorage loss by a clinically significant margin. |
| Best Evidence |
(you may view more info by clicking on the PubMed ID link) |
| PubMed ID |
Author / Year |
Patient Group |
Study type
(level of evidence) |
| #1) 32473793 | Liu/2020 | 494 patients in 12 studies | Systematic Review and Meta-analysis | | Key results | This study consistently showed in 11 of 12 included studies that the group treated with mini-implants significantly lowered mesial movement of first maxillary molars compared to the group treated with conventional anchorage devices. The standardized mean difference was -1.48 mm (95% CI = -2.25 to -0.72; P = 0.0002). The study also showed that patients over 18 years of age had a standardized mean difference (SMD) of -1.20 mm (95% CI = -2.01 to -0.39; P = 0.00384) and patients under 18 years of age had SMD of -2.36 mm (95% CI -4.18 to -0.53; P = 0.0113). | | #2) 30350741 | Alharbi/2019 | 271 patients in 7 studies | Systematic Review and Meta-analysis | | Key results | This study comprised of only RCTs consistently showed that the group treated with TADs significantly lowered mesial movement of first maxillary molars compared to the group treated with conventional anchorage devices. The SMD was -2.07 mm (95% CI = -3.05 to -1.08; P <0.001). Furthermore, when the studies with high risk of bias were removed, the SMD was preserved at -1.94 mm (95% CI = -3.46 to -0.42; P < 0.001). | |
| Evidence Search |
Orthodontic mini-implants OR miniscrews AND traditional anchorage AND maximum anchorage |
Comments on
The Evidence |
In Liu’s systematic review, the literature was reviewed up to July 2018. Electronic databases Pubmed, EMBASE, Cochrane Central Register of Controlled Trials, and World Health Organization International Clinical Trials Registry Platform were searched. Twelve studies met the inclusion criteria; four were RCTs, three were prospective controlled trials, and five were retrospective studies. The Cochrane risk of bias tool was used to assess the risk of bias in RCTs and revealed moderate risk of bias. The modified Newcastle-Ottawa Scale was used to assess the quality of non-RCT studies and revealed high quality. However, all the non-RCTs studies did not report the assessment of outcome with independent blinding. The study also showed substantial heterogeneity with I2 = 92.48%. In Alharbi’s systematic review, the literature was reviewed up to March 2018. Electronic databases Pubmed, Scopus, Cochrane Database of Systematic review, and Cochrane Central Register of Controlled Trials were searched. Seven studies met the inclusion criteria and all were RCTs. The Cochrane risk of bias tool was used to assess the risk of bias in RCTs and revealed four studies with high risk of bias and three studies with low risk of bias. The study showed substantial heterogeneity with I2 = 88% and when the high risk studies were excluded the I2 = 93%. Studies with higher quality RCTs with larger sample sizes would provide more conclusive evidence. |
| Applicability |
Patients with class I or class II malocclusion with dentoalveolar protrusion that need premolar extraction and en-masse retraction of anterior teeth also require a treatment modality for anchorage. Anchorage can be achieved with traditional anchorage devices including headgear, transpalatal arches, and Nance buttons and the newer modality of temporary anchorage devices also known as mini-implants or miniscrews. One major factor for clinicians in deciding which anchorage modality to choose would be the need to obtain maximum anchorage through minimizing the undesirable mesial first molar movement. The lesser mesial movement of molars provides more space for anterior teeth retraction. Both of the studies showed that TADs were more effective than traditional anchorage devices in achieving this. Both studies incorporated patients that were both male and female, adolescent and adult, and from varied geographic locations. These elements help generalize the applicability of the results. Liu’s study also showed greater maximum anchorage achieved in patients over 18, possibly due to higher cortical thickness that provide more stability to TADs in adults. It is also important to note that there are other factors involved for clinicians deciding which treatment modality to use for anchorage including cost, treatment duration, patient perceived benefits, and adverse effects. |
| Specialty/Discipline |
(Orthodontics) |
| Keywords |
TADs, mini-implants, miniscrews, skeletal anchorage, traditional anchorage, maximum anchorage, malocclusion
|
| ID# |
3492 |
| Date of submission: |
09/19/2022 |
| E-mail |
garciao3@livemail.uthscsa.edu |
| Author |
Octavio Garcia |
| Co-author(s) |
Kelly Lemke DDS MS |
| Co-author(s) e-mail |
lemkek@uthscsa.edu |
| Faculty mentor/Co-author |
Brent Callegari DDS MS |
| Faculty mentor/Co-author e-mail |
callegari@uthscsa.edu |
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?) |
post a rationale |
| None available | |
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Comments and Evidence-Based Updates on the CAT
(FOR PRACTICING DENTISTS', FACULTY, RESIDENTS and/or STUDENTS COMMENTS ON PUBLISHED CATs) |
post a comment |
| None available | |
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