The impact of buccal corridors on smile attractiveness

The aim of this study was to assess the impact of various sized buccal corridors (BCs) on smile attractiveness. One female smiling photograph, displaying first molar to first molar (M1-M1), was digitally altered to produce (1) smiles that filled 84, 88, 92, 96, and 100 per cent of the oral aperture; (2) second premolar to second premolar smiles (PM2-PM2) that filled 84, 88, 92, and 96 per cent of the oral aperture; and (3) smiles with asymmetrical BC that filled 88, 90, 94, and 96 per cent of the oral aperture. The 18 smiles produced were evaluated by 82 orthodontists (70 males and 12 females) and 94 laypeople (40 males and 54 females). Paired t-tests were used to evaluate differences within the orthodontist and laypeople groups: independent t-tests were used to compare the two groups. The effect of age and gender on the ratings was evaluated by two-way analysis of variance. Orthodontists and laypeople rated smiles with small BCs as significantly (P < 0.05) more attractive than those with large BCs. Orthodontists rated M1-M1 smiles as more attractive than PM2-PM2 smiles, whereas laypeople preferred PM2-PM2 smiles. Orthodontists rated only two of eight asymmetrical smiles as less attractive than would be expected for symmetrical smiles with similar arch widths; laypeople did not rate any asymmetrical smiles as less attractive than would be expected. Rater age and gender did not significantly influence the impact of BCs on smile attractiveness.