Purpose The inclination of the occlusal plane is important for diagnostic purposes, and it also acts as a guideline for designing occlusal rehabilitation therapies. When all teeth are lost, different landmarks have been employed to establish the occlusal plane. Hence, this study aims to compare the mandibular plane with the lower occlusal plane in dentulous patients. Methods A digital photograph of the right and left facial profiles was obtained of the angle between the intraoral occlusal plane (represented by a modified Fox plane) and mandibular plane (represented by a metallic scale placed on the lower border of the mandible) in a standard position. The angle was calculated using Microdicom software, and results were statistically analysed using Mann Whitney U test. Results The average angle between the occlusal plane and mandibular plane was 6 degrees and the difference in angle between the right and left sides was not statistically significant. Conclusions The lower occlusal and mandibular plane though not parallel to each other clinically, may serve as an initial guide in the establishment of the occlusal plane.
Ragher et al. (Tue,) studied this question.