Influence of maxillary incisor level of exposure on the perception of dentofacial aesthetics among orthodontists and laypersons

Does the presence of maxillary midline diastema influence the perception of dentofacial esthetics in video analysis?

OBJECTIVE

To evaluate the influence of a midline diastema on dentofacial esthetic perceptions of orthodontists, restorative dental specialists or prosthodontists, and laypersons in a frontal facial evaluation performed by means of video.

MATERIALS AND METHODS

Two individuals aged between 20 and 25 years, one of each gender, with presence of a midline diastema were selected. An acrylic resin mockup was made of the maxillary anterior region, simulating ideal conditions of smile esthetics. Four standardized frontal view videos of the complete face were filmed of each individual in the following situations: with the ideal smile (unchanged mockup) and with the presence of midline diastemas of 0.5, 1.0, and 1.5 mm created by the mockup. In all videos, the patient said a certain sentence and, at the end, simulated a posed smile. Dentofacial esthetic perceptions of all four videos of each individual were evaluated by 51 orthodontists, 51 restorative dental specialists or prosthodontists, and 51 laypersons by means of visual analog scales. Data were evaluated using analysis of variance and Tukey post hoc test, with the level of significance set at 5%.

RESULTS

The most attractive videos for all groups of examiners were those without diastema and with a diastema of 0.5 mm, for both the woman and the man. For a diastema of 1 mm or 1.5 mm, the dentofacial characteristics were considered unesthetic.

CONCLUSIONS

Diastemas equal to or greater than 1 mm negatively influence dentofacial esthetics in a frontal facial evaluation performed by means of video.

Does the vertical position of maxillary central incisors in men influence smile esthetics perception?

INTRODUCTION

The aim of this study was to investigate whether there is any influence on the perception of smile esthetics among orthodontists and laypersons, with regard to different vertical positions of the maxillary central incisors.

METHODS

Frontal smile photographs digitally altered at full-face view and close-up view of 2 adult men aged between 20 and 30 years were used. Six vertical positions of the central incisors were created, with changes of 0.5 mm. The images were randomly assembled in an album that was presented to 53 orthodontists and 53 laypersons, who evaluated the attractiveness of the images by using visual analog scales. Comparison among the images was performed using 1-way analysis of variance, with Tukey post-hoc test. To compare the distribution of the mean scores between the full-face and close-up smile views, and between orthodontists and laypersons, the Student t test was used. The level of significance was established at 5%.

RESULTS

The best evaluations presented the following: (a) the gingival margins of the central incisors corresponded to, or were up to, 1 mm below the line of the canine gingival margins, and (b) the incisal step between the central and lateral incisors was from 1.0 to 2.0 mm. The smiles considered least attractive showed (a) the central incisor gingival margins were 1.0 mm above or 1.5 mm below the canine gingival margins, and (b) no step, or a step of 2.5 mm, between the central and lateral incisors.

CONCLUSIONS

The results of this study suggested that, in men, slightly extruded central incisors were esthetically more attractive than intruded incisors.

Do different vertical positions of maxillary central incisors influence smile esthetics perception?

INTRODUCTION:

The purpose of this study was to determine the perception of smile esthetics among orthodontists and layperson, with respect to different maxillary central incisors vertical positions in full-face and close-up smile analyses.

METHODS:

Frontal photographs of the smiles of two adult women were used. Images were altered to create a symmetrical image with the gingival margin levels of the maxillary canines matching the central incisors and a 1.0-mm central-to-lateral incisal step. Later, the images were altered in order to create six different central incisor vertical positions in 0.5-mm increments. The images were randomly assembled in an album, which was given to 114 judges, 57 orthodontists and 57 laypersons, who were asked to evaluate the attractiveness of the images using the visual analog scale. The data collected were statistically analyzed by means of 1-way analysis of variance with the Tukey post-hoc test and the Student t test.

RESULTS:

The highest rated smiles showed two notable characteristics: a) the central incisor gingival margins matched or were 0.5 mm below the line of the canine gingival margins and; b) the central-to-lateral incisal step was 1.0 to 1.5 mm. The worst smiles showed two notable characteristics: a) the central incisor gingival margins were 1.0 mm above or 1.5 mm below the canine gingival margins and; b) no step between the centrals and laterals or a 2.5-mm step.

CONCLUSION:

The vertical position of the maxillary central incisors significantly affected the perception of the smile esthetics, whereas slightly extruded central incisors were more esthetically preferred than intruded.