Determination of the relative parallelism of occlusal plane to three ala-tragal lines in various skeletal malocclusions: A cephalometric study

Abstract

Establishment of a proper occlusal plane is needed for developing an occlusion that is compatible with the biomechanics of a stomatognathic system. There has been a great deal of controversy regarding the anatomic reference point/s taken for identifying the Camper's plane (Ala-Tragus) to which the occlusal plane is oriented parallel in regular complete denture Prosthodontic practice. There has been no study in literature to correlate the occlusal plane to the Camper's plane in various skeletal malocclusions using landmarks on a lateral Cephalogram. The aim of the study is to determine the relative parallelism of the occlusal plane to ala-tragal lines in various malocclusions. A total of sixty subjects belonging to Class I, Class II and class III malocclusions were selected for the study. Markings with radiopaque marker of 1 mm diameter were adhered against the superior, middle and inferior border of the tragus and against the lower borer of ala of the nose. Lateral cephalograms were obtained for all of the patients. Tracing was performed for all of these radiographs. Analysis of Variance (ANOVA) test and Post-Hoc test of Bonferroni were used to compare the angles formed at the superior, middle and inferior borders with the occlusal plane. The result from the present study showed that in Class I and Class III malocclusion, the line drawn from the lower border of ala of the nose to the inferior position of the tragus (Camper' plane C) was relatively parallel to occlusal plane; and, in Class II malocclusion, the line drawn from the lower border of ala of nose to middle border of tragus (Camper's plane B) was relatively parallel to occlusal plane.