Effectiveness of different autologous platelet concentrates for orthodontic canine retraction following premolar extraction: a systematic review and meta-analysis

Autologous platelet concentrates (APCs) have been increasingly used to accelerate orthodontic canine retraction; however, their effectiveness and associated clinical outcomes remain unclear. To evaluate the effectiveness of platelet-rich plasma (PRP), injectable platelet-rich fibrin (i-PRF), and leukocyte-platelet-rich fibrin (L-PRF) in accelerating canine retraction following premolar extraction and to summarize associated clinical outcomes including canine movement patterns, anchorage loss, and treatment-related adverse outcomes. A systematic review and meta-analysis was conducted by searching PubMed, Embase, Web of Science, Scopus, and the Cochrane Library up to April 24, 2026. Randomized and controlled clinical studies involving orthodontic patients undergoing canine retraction following premolar extraction and evaluating the effects of APCs were included. Random-effects meta-analyses and GRADE assessments were performed when appropriate. 28 articles representing 26 unique studies were included in the qualitative synthesis, of which 16 studies were included in the meta-analysis. PRP demonstrated the most consistent evidence of accelerated canine retraction during the first month of treatment. i-PRF showed statistically significant effects across multiple observation periods, whereas L-PRF exhibited an earlier response pattern, with effects observed from the first week through the third month. However, substantial heterogeneity was observed in the i-PRF and L-PRF analyses. No consistent effects were identified on canine movement pattern or anchorage loss. No consistent increase in serious adverse outcomes was observed, although transient post-procedural pain and discomfort were reported following PRP and i-PRF administration. Moderate-certainty evidence supported the first-month effect of PRP, whereas all remaining findings were supported by low- to very low-certainty evidence. APCs may accelerate orthodontic canine retraction following premolar extraction without clear evidence of increased adverse outcomes. The most reliable evidence currently supports a possible short-term benefit of PRP during the first month of treatment. Although i-PRF and L-PRF demonstrated potential effects over longer or earlier observation periods, the certainty of evidence remains low and substantial heterogeneity limits confidence in these findings. Further well-designed randomized controlled trials are required to determine the clinical relevance of these effects and to establish optimal application protocols. PROSPERO (CRD 420261377123).