A study of the suitability of two methods used for describing the occlusal plane

In this study an effort was made to determine which of the two commonly used methods of occlusal plane determination more precisely depicts changes induced by treatment or growth. Longitudinal lateral cephalometric radiographs of 70 individuals, 40 orthodontically treated and 30 with clinically acceptable occlusion, were used. Following an analysis of outcomes obtained through the conventional application of the Downs occlusal plane method and the functional occlusal plane method, there are indications that: 1) the Downs method may provide a better description of what happens to the occlusion following treatment; 2) the notion that the plane reconstructed using the functional method actually represents the location at which the occlusal function takes place is unsubstantiated; and 3) since it is possible that the results of this study could be influenced by the types of malocclusion, skeletal patterns, and methods of orthodontic treatment, further analyses are called for in order to make more conclusive determinations about these methods.