Aesthetic evaluation of the labiolingual position of maxillary lateral incisors by orthodontists and laypersons

Abstract

BackgroundsThe maxillary anterior teeth play a crucial role in smile aesthetics. As for maxillary lateral incisors, most studies concentrated on its size, incisor edge level, inclination, et al. However, the aesthetic effect of lateral incisor movement in spatial position has not been studied yet. Therefore, the purpose of this study was to explore the influence of labiolingual position of maxillary lateral incisors on the aesthetic perception of orthodontists and laypersons and different gender groups.MethodsA photograph of a male's smile was selected. iOrtho7.0 software (Time Angel, Wuxi, China) was used to edit the three dimensional (3D) dental models. By referring to the 3D models, the photograph was digitally processed to create seven images with different labiolingual positions of the maxillary lateral incisors in 0.5 mm increments (+ indicates labial movement and -indicates lingual movement). Eighty-six orthodontists and one hundred sixty-one laypersons were asked to evaluate images using a visual analog scale. Data were analyzed by Student t-test and One-way analysis of variance with post hoc test.ResultsThere was no significant difference between the perception of males and females (P > 0.05). Orthodontists assigned lower scores to all images than laypersons. +1.5 mm was considered as the least attractive smile by orthodontists while + 1.5 mm and − 1.5 mm were regarded as the least attractive ones by laypersons. 0 mm was rated the most attractive by all judges (P < 0.05). Between the 0 mm and − 0.5 mm, laypersons observed the difference but orthodontists did not.ConclusionsThe labiolingual position of maxillary lateral incisors does affect the perception of smile esthetics. Although orthodontists gave lower score to each image than laypersons.

Long-term follow-up of Liou-Alternate rapid maxillary expansion and constriction

“…The intraoral photographs presented in Figure 1 seem to be reproduced from an earlier publication by the authors. 1 Although it has served well to illustrate the design of the appliance, photographs from the current sample of a noncleft, nonsyndromic Class III malocclusion would have been more representative.…”

Authors’ response

“…The intraoral photographs presented in Figure 1 seem to be reproduced from an earlier publication by the authors. 1 Although it has served well to illustrate the design of the appliance, photographs from the current sample of a noncleft, nonsyndromic Class III malocclusion would have been more representative.…”

“…We measured PFH/AFH ratio, and there was a mild nonsignificant reduction after treatment and a return to a physiological increase in the T1t (S-Go/N-Me/PFH/AFH ratio at T0, 62.9 6 4.3%; T1, 62.1 6 4.2%; T1 À T0, À0.8 6 1%; Tlt, 64.1 6 5.8%; Tlt À T1, 2.0 6 1.6%). Possibly, given that most of the differential growth between PFH and AFH occurs in adolescents aged between 11 and 13 years (Lapter, 2003), 1…”

Esthetic evaluation of incisor inclination and anterior vertical facial height

“…To present accurate frontal shape of the incisor, the angular alters of incisor inclination can be achieved in three-dimensional models, which can provide references for subsequent modification in Photoshop software by frontal screenshot. 2 Second, different vertical facial patterns can lead to different esthetic criteria of facial attractiveness, 3 and the evaluation results may vary in other facial patterns. Therefore, comparing the effect of incisor inclination and anterior facial height on facial attractiveness among different facial patterns will be the next step.…”