SIGNIFICANCE OF THE CANT OF THE POSTERIOR OCCLUSAL PLANE IN CLASS-II DIVISION-1 MALOCCLUSIONS

In studying a group of fifty adult females with Class II division 1 ma locclusion, it was evident that the skeletal problems of this malocclu sion involved small, retruded mandibles accompanied by backward rotati on. This skeletal pattern was considered to be influenced by the verti cal dimension of the upper dentition in the buccal segment for mandibu lar function. The anterior and the posterior occlusal planes were exam ined to gain a detailed assessment of the relationship between the den tal and the skeletal patterns. The findings indicated that the steep c ant of the posterior occlusal plane was strongly correlated with the f ollowing: 1. Small, retruded mandible with backward rotation as the sk eletal pattern. 2. Short vertical height of the upper second molars an d distal inclination of the upper molars as the dental pattern. The in creased vertical height of the lower second premolars was found to be related to backward rotation of the mandible. In treating skeletal Cla ss II division 1 malocclusions, this study indicated that control of t he vertical dimension of the posterior teeth is extremely important.