Canting of the occlusal plane: Perceptions of dental professionals and laypersons

OBJECTIVES To determine if canting of the occlusal plane influences esthetic evaluation of the smile among orthodontists, dentists and laypersons. STUDY DESIGN A frontal photo of a smile with 0 occlusal plane canting in relation to the bipupillary plane was modified using Adobe Photoshop C3 (Adobe Systems Inc, San José, California) to generate two images with occlusal plane inclinations of 2 and 4 . The three images were evaluated esthetically by orthodontists (n=40) general dentists (n=40) and laypersons (n=40). Each image was awarded a score as follows: 1=esthetically acceptable; 2=moderately acceptable; 3=esthetically unacceptable. Evaluators also placed the three images in order in preference. Data were analyzed using the Kruskal-Wallis (p<0.05) and the Mann-Whitney tests, applying the Bonferroni Correction (p<0.016). RESULTS No significant differences (p> 0.05) were found between the three groups for 0 and 2 cants (median for orthodontists=1; general dentists=1; laypersons=1). Orthodontists (median score=3) made evaluations of the image with 4 occlusal plane that were significantly different from general dentists (median=2) and laypersons (median=2). All three groups put the 0 image in first place in order of esthetic acceptability, the 2 image in second place and the 4 image in third place. Orthodontists placed the 0 image in first place with significantly greater frequency (p<0.016) than laypersons. CONCLUSIONS Occlusal plane canting of 0 and 2 were evaluated as esthetically acceptable by the three groups. The 4 occlusal plane cant was evaluated more negatively by orthodontists than by general dentists and laypersons. All three groups placed the 0 image in first place of esthetic acceptability, 2 in second place and 4 in third. Orthodontists put the 0 image in first place with significantly greater frequency than laypersons.