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

Abstract

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 0º 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 2º and 4º. 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 0º and 2º cants (median for orthodontists=1; general dentists=1; laypersons=1). Orthodontists (median score=3) made evaluations of the image with 4º occlusal plane that were significantly different from general dentists (median=2) and laypersons (median=2). All three groups put the 0º image in first place in order of esthetic acceptability, the 2º image in second place and the 4º image in third place. Orthodontists placed the 0º image in first place with significantly greater frequency (p<0.016) than laypersons. Conclusions: Occlusal plane canting of 0º and 2º were evaluated as esthetically acceptable by the three groups. The 4º occlusal plane cant was evaluated more negatively by orthodontists than by general dentists and laypersons. All three groups placed the 0º image in first place of esthetic acceptability, 2º in second place and 4º in third. Orthodontists put the 0º image in first place with significantly greater frequency than laypersons. Key words:Canting, perception, smile, orthodontics, dental esthetics.

Layperson's preference of the transverse occlusal plane in asymmetric facial model

“…Some studies compared directly dentists vs laypersons, finding tolerances of 1 mm for dentists and 3 mm for laypersons, 19 others found similarities between both groups. 20,21 The present study found the threshold at 2 (or the equivalent of 1 mm 19 ), corroborating the results of Padwa et al, 22 showing a slightly higher sensitivity of the laypersons interviewed compared to the literature. It is evident that there is a high variability of results in the literature regarding was to see if the nose and chin inclinations affected the ratings considering which side of the cant was involved.…”

“…Some studies compared directly dentists vs laypersons, finding tolerances of 1 mm for dentists and 3 mm for laypersons, others found similarities between both groups . The present study found the threshold at 2° (or the equivalent of 1 mm), corroborating the results of Padwa et al, showing a slightly higher sensitivity of the laypersons interviewed compared to the literature.…”

Perception of facial, dental, and smile esthetics by dental students

“…Buccal corridor was difficult to be perceived even by dental specialist . Even more, 4 ° occlusal plane cant was considered normal by general dentists . Padwa et al reported that the perception of occlusal plane canting depends on the degree of inclination rather than the levels of experience of the observers.…”

Évaluation esthétique des asymétries dentaires et gingivales

“…Pour cette raison, les praticiens consid erent qu'une simple restauration du bord incisif serait plus simple à r ealiser qu'une modification du contour gingival. Among professional respondents, prosthodontists are most critical, followed by orthodontists, as shown by by Olivares et al [20]. N eanmoins, il est evident que dans une evaluation individuelle des images modifi ees celles qui ont et e jug ees esth etiques par tous les r epondants etaient celles montrant le bord incisif asym etrique de l'incisive centrale sup erieure, plus courte de 0,5 mm (n o 4) et la migration gingivale asym etrique de 2 mm de l'incisive centrale sup erieure (n o 8).…”

“…Janson et al [16], cependant, dans une revue syst ematique, ont conclu qu'une d erive de la ligne m ediane maxillaire jusqu'à 2,2 mm est esth etiquement acceptable pour les orthodontistes comme pour les non-professionnels. Parmi les r epondants professionnels, les dentistes proth esistes etaient les evaluateurs les plus critiques, suivis des orthodontistes, en concordance avec l' etude d'Olivares et al [20]. Cette disparit e au niveau des evaluations esth etiques est peutêtre due aux diff erences de mat eriel et de m ethode utilis es dans leurs etudes.…”