Rationale of treatment for Class II division 2 malocclusion.

Class II, division 2 malocclusion is a clinical entity which presents considerable difficulty in the provision of a stable treatment result. This article sets out the problems encountered, reviews teaching on the subject over a 20-year period and attempts to rationalize the current approach to treatment. The rationale presented shows the three-dimensional nature of the occlusal problem, and discusses the justification for expansion and proclination of lower incisors in relation to soft tissue influences and stability. The importance of correcting edge-centroid relationship and reducing inter-incisor angle is stressed. Non-extraction therapy, with some lower arch expansion and incisor advancement, is recommended and the reasoning behind this is explained with a case example to illustrate the points involved.