Comparison of Effect of Twin Block and Fixed Functional Appliances on Lower Incisor Inclination – A Systematic Review Twin Block vs Fixed Appliances: Incisor Inclination

Abstract

Introduction: Class II malocclusions, prevalent in orthodontic practice, necessitate effective treatment for optimal dental alignment and enhanced facial aesthetics. Functional appliances, either removable or fixed, address these concerns. Patient compliance is crucial and fixed functional appliances reduce this need. However, the literature indicates a notable forward movement of lower incisors in patients treated with both removable and fixed functional appliances. This systematic review aims to compare the impact on lower incisor inclination of twin block and fixed functional appliances.

Materials and Methods: Eligible studies, retrieved from electronic databases and orthodontic journals, underwent a selection process. Inclusion criteria involved participants with skeletal class II malocclusion treated with fixed functional or twin-block appliances in retrospective and prospective studies.

Results: Six studies, five retrospective and one prospective, met the inclusion criteria. The studies compared lower incisor proclination of twin block and various fixed functional appliances such as Forsus, Herbst, and XBow. The risk of bias assessment revealed five studies with low risk and one with high risk due to participant selection bias.

Conclusion: Four out of six studies demonstrated a significant increase in mandibular incisor proclination for twin block as well as fixed functional appliances. However, fixed functional appliances consistently led to a more significant effect.