The treatment study group of the BSSO. A case report

Orthodontic treatment succeeded in correcting the incisor relationship by a combination of retroclination of the lower labial segment by 2 degrees with a reduction of 1.5 mms in APo and a proclination of the upper labial segment by 7 degrees. There would appear to have been little change in the underlying skeletal pattern. The increase from 1 to 4 in the WITS analysis appears to be related to the downward and anterior change in inclination of the functional occlusal plane. Apart from a possible slight increase, there appeared to be little change in the Skeletal III pattern during retention and the subsequent 33 months. The incisor relationship held with a compensatory proclination of the upper labial segment. The functional occlusal plane reverted partially to its original inclination with a reduction in the WITS analysis to 2.