Outcomes of Early Class II Malocclusion Treatment : A Systematic Review

Aim: To undertake a systematic review of the evidence supporting early treatment (before the age of 10) of Class II malocclusion, with special reference to short and long-term outcomes: correction of overjet, dental relationships, improvement in intermaxillary relationships, soft tissue profile, associations to Temporomandibular Disorders (TMD), quality of life, incidence of trauma and cost-effectiveness. Material and methods: Four databases were searched, from January 1960 to October 2017. Inclusion criteria were randomized controlled or controlled trials reporting short or long-term effects on dental or basal relationships, soft tissue profile, associations to TMD, quality of life, incidence of trauma, or costs. The quality of evidence was scored according to GRADE. Results: 297 studies were identified and 23 satisfied the inclusion criteria for full evaluation. The quality of evidence was high in 5 studies, moderate in 3, and low in 15. There is lack of data on long-term outcomes and stability, thus all evidence is based on short-term results. There is high level of evidence that early treatment of Class II malocclusion with functional appliances reduces overjet and improves skeletal relationships, moderate evidence that headgear reduces overjet and restrains forward growth of the maxilla, but insufficient evidence to determine how early treatment influences soft tissue profile, TMD, quality of life, incidence of trauma or treatment-related costs. Conclusion: There is moderate to high evidence that in the short term, early treatment of Class II malocclusion division 1 reduces overjet and improves skeletal relationships