Impact of variations in maxillary lateral incisor dimensions on smile esthetics

Dentofacial esthetics has become an increasingly important topic in recent years among orthodontic patients, so it is suggested that the esthetic perspectives of clinicians and patients be considered when planning orthodontic treatment. The maxillary lateral incisors play a key role in smile esthetics. The purpose of this study was to investigate the effect of dimensional changes of the maxillary lateral incisors on smile esthetics as perceived by orthodontists, general dentists, and laypersons.

This was a descriptive cross-sectional study. A photograph showing an attractive smile was selected. The dimensions of the maxillary lateral incisors were edited with photograph editing software to represent variations in width, crown length, gingival height, and mesial angulation. Groups of orthodontists, general dentists, and laypersons (n = 16 per group) evaluated the smile attractiveness of the images using the Likert scale according to smile esthetics criteria. Statistical analysis was performed using SPSS software (version 25) and Kruskal-Wallis statistical test. The significance level was set at 0.05.

There was no significant difference between mean scores of lateral incisor golden proportion changes, vertical crown length changes, gingival height changes, and mesial angulation changes (P >0.05). All groups found 1 mm more incisally positioned gingival height of lateral incisor than the central incisor and 1 mm more apically positioned incisal edge of lateral incisor than the central incisor to be the most attractive. In the group of orthodontic specialists, the 20° mesial angulation and in the other 2 groups the 10° and 15° mesial angulation had the highest score.

Partial deviations from the ideal esthetic proportions were not detected by laypersons, general dentists, or orthodontists and are acceptable and even attractive from the point of view of patients. Some adherence to these ratios will be acceptable in dental treatments.