Effectiveness of extraction of primary canines for interceptive management of palatally displaced permanent canines: a systematic review and meta-analysis.

ABSTRACT

Background: Although extraction of primary canines in the mixed dentition has been suggested as a measure to prevent impaction of palatally displaced permanent canines (PDCs), the relevant evidence has been inconclusive. Objective: To assess the effectiveness of this practice and investigate the quality of the evidence. Search methods: Search without restrictions in 15 databases and hand searching until April 2017. Selection criteria Randomized clinical trials comparing extraction of primary canines in the mixed dentition to no treatment. Data collection and analysis: Following study retrieval and selection, data extraction, and individual study risk of bias assessment using the Cochrane Risk of Bias Tool, the random effects method of combining treatment effects was used. The overall quality of the available evidence was assessed with the Grades of Recommendation, Assessment, Development, and Evaluation approach. Results: Finally 5 studies were identified involving 214 individuals, followed for up to 48 months post-intervention. Two studies were at low and the rest at high risk of bias. Although at the 12-month evaluation, extraction of the primary canine did not result in a statistically significant difference [risk ratio (RR) 1.537; 95% confidence interval (CI) 0.656-3.601, P = 0.323; 1 study, n = 67 individuals], beyond 12 months a benefit was noted (RR 1.784; 95% CI 1.376-2.314, P = 0.000; 5 studies, n = 214 individuals; I2 = 0%). Analysis of the studies at low risk of bias confirmed the above-mentioned result (RR 1.713; 95% CI 1.226-2.394, P = 0.002; 2 studies, n = 91 individuals; I2 = 0%; moderate quality evidence). No difference was observed regarding root resorption of adjacent permanent teeth (RR 0.602; 95% CI 0.277-1.308, P = 0.200; 1 study; n = 67 individuals; moderate quality evidence). Conclusions: Extraction of primary canines in the mixed dentition may increase the chance of subsequent successful eruption of PDC in the long term. However, better study standardization is necessary.