We read the recent study reported by Pithon et al in the March 2013 issue of the AJO-DO . We sincerely congratulate the authors and appreciate their contributions. However, we have 2 major concerns about this study.

First, the evaluators were required to complete questionnaires and score the images while the images were arranged in increasing or decreasing order of black spaces, but not in random order. This would guide the way of perceiving of the evaluators, who might note the black spaces and score according to the order of the images, but not exactly the size of the black spaces. This could impair the subjectivity of the concept of beauty of each evaluator as well as the objectivity of the results. If the image order were randomized, answers to whether they noted differences between the images might be different from results of this study. Scores and correlations between the 3 age groups might also be different.

Another concern of ours is that different people have different perceptions of smile esthetics. The thresholds of different age groups perceiving the impact of black spaces on smiling esthetics are different. If the size of a black space were below the threshold, laypersons could hardly note it. There is an exaggerated concern by dental specialists rather than an esthetic need. Procedures with a view to correcting the black spaces might be justifiable when the differences in perception were fully discussed with the patient, especially an adult, because the treatment should respect the patient’s wishes.