Effectiveness of micro-implant in vertical control during orthodontic treatment of Class II malocclusion: A systematic review and meta-analysis

Objective: To compare the effectiveness of micro-implant (MI) and conventional anchorage (CA) in vertical control during orthodontic treatment of Class II malocclusion. Materials and Methods Literature search was conducted through Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang Database, VIP, and China Biology Medicine (CBM) from inception to December 2021. Randomized clinical trials (RCTs) and Compared clinical trials (CCTs) were included. Mean differences (MDs) with 95% confidence intervals (CIs) were conducted. A meta-analysis concerning change of mandibular plane, vertical change of upper and lower molar, change of occlusal plane, SNB, chin position and profile was carried out. Results A total of 10662 records were identified in the database search, A total of 19 studies (10 RCTs and 9 CCTs) were included in the final analysis. MI significantly decreased mandibular plane angle and intruded upper molars compared to CA. No significant difference was found in vertical change of lower molars, occlusal plane, SNB, chin position and profile. Conclusion MI seems to be more effective than CA in vertical control during orthodontic treatment of Class II malocclusion. Clinical Relevance MI should be given priority when considering the vertical control of Class II patients, which is beneficial to the counterclockwise rotation of mandible or at least prevention of deterioration of the profile.