Extraction of maxillary primary canines (Cs) and other interceptive interventions in the mixed dentition have been suggested to increase the rate of normal eruption of palatally displaced permanent canines (PDCs). However, the information on the overall effect on PDCs position has not been yet summarized in an evidencebased manner.
To assess whether this practice improves the position of PDCs and to investigate the quality of the evidence.
Unrestricted searches in 8 databases and manual searching of the reference lists in relevant studies were performed up to March 2021 (Medline via PubMed, CENTRAL, Cochrane Database of Systematic Reviews, Scopus, Web of Science, Arab World Research, ClinicalTrials.gov, ProQuest Dissertations and Theses Global).
We looked for data on the positional changes of PDCs (mesial ii inclination, vertical position, canine crown cusp tip to midline) from randomized controlled trials, assessing the various interceptive interventions.
Data collection and analysis:
Following study retrieval and selection, relevant data were extracted, and the risk of bias was assessed using the Cochrane Risk of Bias 2 Tool. Exploratory synthesis and meta-regression were carried out using the random effects model, and the overall quality of the available evidence was assessed with the Grades of Recommendation, Assessment, Development, and Evaluation approach.
Five studies (3 at low risk of bias) were identified, involving 238 individuals, followed for up to 18 months post-intervention with orthopantomograms or cone beam computed tomography. Exploratory data synthesis showed that PDCs’ position improved more in the extraction sites compared to non-extraction. Analysis of the studies at low risk confirmed the above observations (6 and 12 months). Improvements were observed in patients using headgear after extraction of the Cs compared to extraction alone, but not in patients with double extraction of Cs and first molars. The quality of available evidence was rated as moderate at best.
Interceptive interventions in the mixed dentition may improve the position of PDCs. However, further studies are warranted in order to determine the clinical significance of the changes.||en_US