Early treatment of severe class II division 1 malocclusions

The treatment of children with severe Class II division 1 malocclusions presents a dilemma to the orthodontist. It is now believed that orthodontic appliances have a clinically significant effect in promoting forward mandibular growth.¹ If the malocclusion is so severe that mandibular advancement surgery is a likely outcome, would early orthodontic treatment be putting the child through unnecessary therapy and complicating later treatment by reducing the overjet?

However, early treatment would seem to have some proven benefits such as the reduction of the risk of trauma to the anterior teeth² and reduction of bullying during the period until the patient was old enough to have surgery.³ Providing teeth have not been extracted, the possibility of increasing the overjet and carrying out mandibular advancement surgery would still be an option.

Two cases are described where a very large overjet (over 15 mm) was successfully reduced without the need for extraction. The treatment involved a functional appliance phase using the simple Class II corrector (Button and Bead appliance), as described by Spary and Little,⁴ followed by fixed appliances. The conversion to fixed appliances can be a problem if pre-adjusted edgewise appliances, like the Straight-Wire Appliance®, are used. This is because the upper teeth are tipped distally during the functional appliance treatment, so that they will tend to move forwards as the upper teeth are aligned. Using Begg or Tip-Edge® brackets in the upper jaw prevents this proclination and the teeth can be uprighted later when anchorage can be supported by Class II elastics. This technique has been described by Little and Spary.⁵