Effectiveness of prefabricated myofunctional appliances in the treatment of Class II division 1 malocclusion: a systematic review

Abstract

Background: Prefabricated myofunctional appliances (PMAs) are widely advocated for correcting Class II division I malocclusion. However, their effectiveness is associated with a high amount of uncertainty within contemporary literature.

Objectives: The aim of this review was to systematically examine the available literature regarding the effectiveness of PMAs in treating Class II division 1 malocclusion in children and adolescents.

Search methods: Comprehensive unrestricted electronic searches in multiple databases as well as manual searches were conducted up to August 2018.

Selection criteria: Randomized controlled trials (RCTs) and non-randomized studies (NRS) matching the eligibility criteria.

Data collection and analysis: Two independent review authors were directly involved in study selection, data extraction, and bias assessment. The Cochrane risk of bias tool and the ROBINS-I tool were used for assessing the risk of bias. Quantitative pooling of the data was undertaken with a random-effects model with its 95% confidence interval (CI).

Results: Three RCTs comparing PMAs to activators and three NRS comparing PMAs to untreated controls met the inclusion criteria. On a short-term basis, exploratory quantitative synthesis indicated that the activators were more effective than the PMAs in correcting overjet with a mean difference of (1.1 mm; 95% CI: 0.44 to 1.77). On a long-term basis, there were no significant differences between the two appliances. Qualitative synthesis indicated less favorable soft tissue changes as well as patient experiences and compliance with the PMAs when compared to the activators. However, PMAs were associated with reduced costs compared to customized activators and modest changes when compared to untreated controls.

Conclusions: On a short-term basis, low quality of evidence suggests that PMAs were generally less effective than the activators in treating Class II division 1 malocclusion. The main advantage of PMAs seems to be their reduced costs. These results should be viewed with caution, as a definitive need for high-quality long-term research into this area is required.

Registration: PROSPERO (CRD42018108564).