An 11-year-old female presented with a class II division 1 malocclusion on a moderate skeletal class II pattern with reduced vertical dimensions complicated by an increased overjet (11mm), increased overbite, generalized spacing and bi-maxillary proclination.

The aetiology of this malocclusion is multi-factorial.

The moderate skeletal class II discrepancy resulted in an increased overjet and class II molar relationship. The overjet was exacerbated by the presence of a lower lip trap. The generalized spacing was a result of an underlying dento-alveolar disproportion. This was compounded by bi-maxillary proclination, which arose due to resting soft tissue pressures and dento-alveolar compensation.

TREATMENT PLAN

• Integration of twin block functional and sectional lower fixed Herbst appliancee
• Continuation of functional appliance wear at night
only
• Use of headgear
• Inter-arch class II elastic traction following fixed
appliance placement

The prognosis for long-term stability of class II correction is good in this case, as the new maxillary incisor position will be controlled by the lower lip following the achievement of lip competence.