[Control of vertical dimension in the Root technique. Part 2. Class II]

Hyperdivergent, or high angle, Class II skeletal malocclusions require a reduction in that angle so that an optimal counter-reduction of the mandible can be obtained. Four of these types of cases are analyzed here to show: in the first, treated without extractions, the limitations of this approach: the poor esthetic result derives from the incomplete retraction of incisors because of the occlusal deficits further correction would have incurred; in the second, treated with extractions of upper and lower first bicuspids, that a reduction of the angles SNM from 45 degrees to 40 degrees, FMA from 27 degrees to 24 degrees and ANB from 90 to 40 was obtained; in the third case, treated with extractions of the upper first bicuspids and the lower second bicuspids, that a counter-rotation of the mandible was required in order not to aggravate the esthetic problem while the dental deformity was being corrected. Angle SNM was reduced from 30 degrees to 25 degrees, FMA from 26 degrees to 20 degrees, and ANB from 7 degrees to 2 degrees; and, in the fourth case, where an atypical extraction scheme was elected, that an effective orthodonticsurgical alternative is available. Thanks to an anchorage conception specifically designed for this case by T. Root allowing for extraction of upper first molars, angle SNM was reduced from 38 degrees to 35 degrees, FMA was changed from 28 degrees to 23 degrees, and ANB dropped from 10 degrees to 3.5 degrees.