Comparison of Digital and Paper Assessment of Smile Aesthetics Perception

Despite the widespread of assessment of smile aesthetic perception in many areas, there has yet to be a direct comparison of digital and paper-based photographs for the assessment of smile aesthetics. Here we compared digital and paper-based photographs representing different smile aesthetic features using visual analog scale (VAS) scoring.

One hundred students were randomly recruited from a university campus. Participants were asked to record their perception of smile aesthetics via paper and digital-based platforms. The minimum clinically important difference between platforms was set at 15 mm. The percentage of participants who rated smile attractiveness worse on digital images was recorded. The paired one-tailed Student's t test was used to determine differences between digital and paper platforms, and Bland-Altman analysis and intraclass correlations (ICCs) were used to test for agreement between paper and digital photographs.

Ninety-nine subjects participated, 55 men (mean age = 22.05, standard deviation [SD] = 1.91) and 44 women (mean age 22.05, SD = 1.84). There were statistically significant differences between paper-based and digital photographs for all images except one (paired t test; P < 0.05). Digital ratings were lower than paper-based ratings for all images, and differences were clinically significant in four out of eight images. A high percentage of participants (50.5%-85.9%) rated smile attractiveness worse on digital images than on paper for all images. There was poor agreement between the two methods as assessed by ICCs and Bland-Altman analysis.

Equivalence between paper and digital images for smile aesthetics cannot be assumed, and paper-based photographs may lead to clinically relevant overestimations of perceived attractiveness. As academic dentistry increasingly relies on digital imaging and sharing in the post-COVID-19 world, further validation of digital platforms for smile aesthetics assessment is warranted, and care should be taken when interpreting the results of studies assessing smile perception based on different platforms.