Three-dimensional analysis to compare parallelism of occlusal planes to the hamular notch-incisive papilla plane in dentulous and edentulous subjects

Abstract

Purpose and Aim: The aim of this study was to evaluate the reliability of hamular notch-incisive papilla (HIP) plane as an anatomical landmark in establishing occlusal plane in edentulous subjects. Materials and Methods: Seventy subjects were selected from the South Indian population, of which 50 were dentulous and 20 were edentulous. Dental stone casts were fabricated for dentulous and edentulous subjects. Dental stone casts of the dentulous and edentulous subjects, along with occlusal rims were analyzed using the three-dimensional analyzing machines. The angles between the occlusal planes and HIP plane were determined using the reference coordinate system based on characteristic points in the dentition on the cusp tips in dentulous casts and on maxillary occlusal rim on edentulous casts. Results: The HIP plane tends to be parallel to the occlusal plane. There is no statistical difference between sexes. Conclusion: The HIP plane is parallel to the natural occlusal plane and can be used as a reference plane to re-establish the occlusal plane in edentulous patients.