Early Treatment of Class II Malocclusion

Abstract

An increased overjet in the primary or mixed dentition is a common reason to seek orthodontic treatment and is usually indicative of an underlying class II malocclusion. This can be due to a variety of factors, including digit sucking, a lip trap or an underlying skeletal II base relationship. Treatment timing has been controversial, with proponents of early treatment claiming it results in greater growth of the mandible and better outcomes for the patient. However, evidence from several large randomised clinical trials investigating early treatment for class II malocclusion have refuted this, essentially showing few clinical differences in outcome for patients who underwent an early course of treatment in the mixed dentition compared to those treated comprehensively in adolescence. However, patients treated early do seem to experience less dentoalveolar trauma than those treated later, although this is generally not severe, and it is debatable whether the slight reduction in risk justifies the cost and burden to the patient of early treatment. Another justification for early treatment is psychological outcome. An increased overjet has been shown to make a child a target for bullying, and there is weak evidence that early treatment can help these patients. If early treatment is embarked upon, there are several modalities that can be used, one of which is a functional appliance. These appliances primarily reduce an increased overjet by dental movement, retroclining the upper incisors and proclining the lowers. There is a small increase in mandibular length, but this disappears with normal growth. Most patients will need a further course of treatment, which will mean maintaining overjet reduction in the transition from early mixed to permanent dentitions. In most cases, it is more efficient and less demanding on patient compliance to delay treatment until early adolescence in the late mixed dentition, as clinical outcome is likely to be the same.