Quantification of Facial and Smile Esthetics

Objective:

To determine whether individuals identified as having superior smiles display differences 1) in accordance with the golden proportion (1.618:1), 2) alignment discrepancies (angle between interpupillary and intercomissure lines), 3) number of teeth revealed in an animated smile and 4) ratios of width/height, when compared to the average population.

Method:

An internet search for “best smile” and “celebrities” identified a total of 108 celebrities (C) and their photographs obtained from the internet. Photographs of dental students were used for the average group(S). With Adobe Photoshop, heights and widths of the anterior teeth, number of teeth and alignment discrepancies were measured and ratios were calculated. Usable photographs were obtained for 90 celebrities and 97 students. The statistical analysis was 2-Way Anova with repeated measures, 2-Way Anova, Mann-Whitney U Test and Wilcoxon Signed Ranks Test. The analysis was conducted with IBM Statistics 19, statistical significance α=0.05.

Result:

Statistically significant differences were found for: alignment discrepancies, p=0.034 (Median(S)=1, 95%CI: 0.777 – 1.223, Median(C)=0.7, 95%CI: 0.493 – 0.907) , and for the number of teeth, p=0.049, where 22.2% of the celebrities revealed 12 teeth versus 6.2% of the controls. In both groups absolute differences from golden ratio (1.618:1) for the width of central incisor/lateral Incisor right and left and for the width of lateral Incisor/canine right and left, were observed through 95% CIs. Gender and left-right were found to be non-significant factors.

Conclusion:

Celebrities identified as having a “best smile” had smaller mean alignment discrepancies and revealed a greater number of teeth in animated smile.