Abstract
A report is presented on eleven Class II cases which had been treated by the Begg technique. The cases were analysed from 1 to 3·5 years following retention, with particular emphasis being placed on changes to the lower labial segment. Where relevant, comparisons are made with growth study standards. The use of the lower incisor—Mandibular planes angle (IMPA) is described and criticized and an alternative linear measurement is used to describe changes in the sagittal position of the lower incisors. The results indicate that despite widely held views, it is possible to obtain stable results, following radical alteration to the lower incisor position. There was a trend towards an overall lingual movement of lower incisor apices.