Evaluation of the attractiveness of different gingival zeniths in smile esthetics

Abstract

Objective: To evaluate the smile attractiveness of different gingival zeniths by general dentists, orthodontists and laypersons and the esthetic perception in the symmetric and asymmetric changes in gingival zeniths. Methods: Posed photographs of five patients were taken and digitally manipulated in Keynote software, in the gingival zenith region, in increments of 0.5 to 1mm in maxillary central and lateral incisors, symmetrically and asymmetrically, in nine different ways for each patient. The photos were then uploaded to a website, where evaluators (general dentists, orthodontists and laypersons) could observe and vote according to their esthetic perception, scoring from 1 to 10, 1 being the least attractive and 10 the more attractive. Kruskal-Wallis and Mann-Whitney tests were used for comparison. Results: Asymmetric gingival zeniths were less attractive than symmetrical gingival zeniths; gingival zenith differences greater than 1mm were perceptible in the smile attractiveness, both by laypersons, general dentists and orthodontists. When comparing maxillary central incisors with maxillary lateral incisors, the aesthetic change performed in the central incisors are more perceptible than those performed in lateral incisors, both symmetrical and asymmetrical. In a general way, orthodontists and general dentists are more critical in the evaluation and perception of gingival zenith changes, with the laypersons perceiving this change only from 1mm of maxillary right central incisor asymmetrical change. Conclusions: Asymmetric gingival zeniths are less attractive than symmetrical ones. Gingival zenith differences greater than 1mm are perceptible in the smile attractiveness. Orthodontists and general dentists are more critical in evaluating smile esthetics.

Comparison of microesthetic patterns in normal occlusion in relation to class I malocclusion treated with extractions of four premolars

“…2,5,[13][14][15] Symmetry between sides has been reported as an important characteristic in microesthetics. 5,12,38 Despite the statistically significant differences found for central incisor width/height symmetry proportion in the Normal Occlusion group, and for the canines width/height symmetry proportion and central incisors gingival zenith in the Class I group (Tables II and III), they were numerically minimal. Then they could be difficult to detect visually and therefore, they may not be perceived as antiesthetic.…”

“…However, this difference was about 0.6 mm and could have not been considered clinically significant. 12,42 As reported for the gingival zenith and connectors, orthodontic treatment might influence gingival contour displacement. 2,7,[13][14][15] The gingival contour of the upper right lateral incisor was significantly greater in the Class I group (Table I), this means that the gingival margin was located more incisal than in Normal Occlusion group.…”

“…Nevertheless, this difference could be considered without clinical significance because in general dentists and laypeople do not perceive microesthetics alterations of less than 1mm. 5,12,38 The lack of difference between groups for width/height proportion could be explained because, this rarely change with orthodontic treatment. This could happen when associated to periodontal intervention, in case of orthodontic extrusion followed by periodontal surgery.…”

“…5,[8][9][10][11] Regarding to gingival zenith, a distal position of this periodontal measure is acceptable for central incisors and canines; and, for lateral incisors, it should be coincident to the center of the dental crown. 2,5,8,12 In healthy conditions, a progressively apical position of connectors is accepted from the midline to posterior teeth. Based on the total maxillary incisor height as parameter, 50% of this measure should be considered for the connector between central incisors, 40% between central and lateral incisors and 30% between lateral incisors and canines.…”

“…13,16,17 Different mesiodistal bracket bonding and second order bends could alter teeth angulation and consequently the gingival zenith. 12,13,16 In some treatments with space discrepancies, interproximal reduction is performed and this could alter teeth width/height proportions, 13,16 and increase gingival connectors. 7,13,15 Gingival contour might be changed through orthodontic extrusion or intrusion, since the gingival margin follows vertical dental crown displacements.…”