The Problem of Overbite in Class II, Division 2 Malocclusion

Abstract

The paper studies 60 Class II, Division 2 malocclusions, from lateral skull radiographs taken before treatment and at least 1 year after the end of retention. In the first part of the paper the nature of the malocclusion is analysed. It usually exhibits a Class II skeletal pattern, and while this is on average milder than for Class II, Division I, there is a marked variation between individuals. Other factors are a high inter-incisal angle, a high lip-line, and in some cases a small lower facial height. The upper and lower facial heights, on the other hand, are not appreciably greater than normal. The results of treatment are then analysed. Successful overbite reduction would seem to be associated with a reduction in inter-incisal angle and a relative lowering of the lower lip-line. Growth appears to be important in achieving overbite reduction. It is suggested that favourable rotation of the mandible may be a factor in overbite reduction in some cases, and this would repay further study. Finally attention is turned to the effect of incisor proclination. This was usually more successful in the lower jaw, but again there was wide individual variation.