Influence of maxillary lateral incisor width ratio on perception of smile esthetics among orthodontists and laypersons.

Objective: This study aimed to analyze the impact of different maxillary lateral incisor width ratios on the perception of smile esthetics among orthodontists and laypersons.

Methods: A smile photograph of a male subject showing the lips and gingival margins was selected. The smile was standardized for maxillary central incisor width proportions and ideally perceived smile esthetics. The maxillary lateral incisor width was symmetrically modified in increments of ratios of the central incisor from a ratio of 4:10 to a ratio of 8:10. The images were analyzed by 283 laypersons and 83 orthodontists who ranked the level of attractiveness using a visual analog scale.

Results: There were significant differences between the esthetic perception of the five different width ratios, and between the orthodontists and laypersons in their evaluations of esthetics (P < 0.0004). There were no significant differences in esthetic evaluations between genders.

Conclusions: For orthodontists, the most attractive width ratio was 5.7:10, while the highest ranked ratio among laypersons was 8:10, although laypersons ranked all ratios very similarly. Both groups ranked the width ratio of 4:10 the lowest. Orthodontists were more critical in their assessment of esthetics.

Clinical Significance: To what proportions or protocol should a peg-shaped maxillary lateral incisor or missing lateral, that is, to be replaced with an implant/crown be restored? This is an important clinical question that is often encountered by the orthodontist and the restoring dentist. The literature suggests that orthodontists and laypeople have different perceptions of smile esthetics, and it is important to have patient centered goals when treatment planning. Further research is necessary to identify the width ratio of which the lateral incisor is perceived to be esthetic as well as the ideal ratio to consider when restoring lateral incisors. This research assessed and compared the perception that orthodontists and laypeople have on smile esthetics regarding different width ratios of lateral incisors.