Efficacy of Twin-block appliance in Class II division 1 of adolescents: A systematic review / 实用口腔医学杂志

ABSTRACT

Objective; To evaluate the efficacy of Twin-block appliance in Class Ⅱ division 1 of adolescents. Methods: Several e-lectronic databases (PubMed, The Cochrane library, Embase, CBMdisk, CNKI, VIP)were searched. Abstract that appears to fulfill the initial selection criteria were selected by consensus and original articles were retrieved. Five Chinese journals were hand searched for possible missing articles. Randomized controlled trials(RCTs) that evaluate the efficacy of Twin-block appliance in Class Ⅱ division I adolescents without any surgical intervention or syndromic characteristics were considered. A comparable untreated control group was required to factor out normal growth changes. The quality of included studies was evaluated according to Cochrane Reviewers Handbook 4.2.6 Meta-analysis was performed by using RevMan 5.0.0 software. Results: Four RCTs including 289 patients were identified. The results of our meta-analysis showed a significant increase on SNB angle, Ar-Gn, Nasolabial angle and Labial-mental fold compared with control group(P<0.05). Whereas overjet, overbite, ANB angle and Ls-E had a significant decrease. In addition, SNA angle and Li-E didnt show statistical significant changes(P>0. 05). Conclusion; In Class II division 1 of adolescents, Twin-block appliance can effectively decrease their overjet, overbite, ANB angle, and induce anterior-posterior growth of mandible. The effect on restrain forward growth of the maxilla was unclear. More RCTs are required to evaluate the efficacy of Twin-block appliance.