Periodontal recessions and aesthetic perception of smile harmony: role of distance and clinical experience of the observer.

Aim: To determine how distance and clinical experience of the observer influence aesthetic perception with respect to variations in anterior soft tissues alterations. Material and Methods: 73 dental students at the University of Bologna, 33 first-year students (preclinical) and 40 fifth-year students (clinical) were recruited for the study. The participants in the study were requested to assign scores to four randomly assigned images of eleven simulated clinical cases of gingival recessions: thirty seconds of observation per photo using Visual Analogue Scale. The observations were performed at pre-defined psychosocial interpersonal distances: 45 cm (limit between “Intimate Space” and “Consultative Space”) and 120 cm (limit between “Consultative Space” and “Social Space”). After two evaluations some minutes passed to reset short-term memory. A total of 292 observations were taken. Statistical analysis A GLM and Scheffè test were applied (α-level was set at 0.05). Results: No significance influence of experience (p=0.07) and distance (p=0.89) on the aesthetic perception with respect to variations in anterior soft tissues alterations was observed. The periodontal alterations significantly influence the scores (p=0.025) and the photo with a single 4mm recession on a canine had the lowest scores. Middle and high evaluations prevailed (low: 0-2, middle: 3-7, high: 8-10; χ2= 35.77, p=0.02). Conclusion: Results evidence that distance and clinical experience do not influence aesthetic perception. Asymmetrical recessions, in both groups, negatively influence smile’s score. Except for important asymmetries the periodontal recession does not seem to influence the smile aesthetic.