Perception of laypersons, orthodontists, and oral and maxillofacial surgeons about the transverse occlusal plane

Abstract

Transverse occlusal plane (TOP) should be parallel to the true horizontal lines of the face (ie, the interpupillary line [IP] and commissural line [CL]). This study aimed to investigate the opinions of laypersons, orthodontists, and oral and maxillofacial surgeons about the impact of imbalanced IP and CL on facial attractiveness. We used a symmetrical face image as the reference. Then, using Photoshop software, we constructed the following 6 photographs: TOP roll relative to CL and IP (3° and 6°) with parallelism of CL and IP, CL roll relative to TOP and IP (3° and 6°) with parallelism of TOP and IP, TOP and CL roll relative to IP (3° and 6°). Consequently, the participants rated the photographs on the basis of their attractiveness. Kruskal-Wallis and Mann-Whitney U tests were used to compare the ratings. One hundred thirty-one laypersons, 22 orthodontists, and 20 surgeons participated in this study. It was found that 51.1% of laypersons, 86.4% of orthodontists, and 70% of surgeons selected the reference photograph as the most beautiful, followed by the photograph with a 3° roll of CL relative to TOP, with parallelism of TOP and IP (29% of laypersons, 31.8% of orthodontists, and 35% of surgeons). Most participants selected the reference photograph as the most beautiful and realized a roll in the horizontal planes up to 3°. The parallelism of the esthetic line of dentition relative to interpupillary is preferred over its parallelism relative to CL.