The effect of teeth and environmental tissue on aesthetic smile perception

Aim: It is to evaluate the consistency between the objective measurements of the measurable dentolabial components on the smile photos taken from volunteer participants and the subjective opinions of the evaluators based on the aesthetic threshold values determined. Method: Posing and smiling photos were taken from 120 volunteer participants studying at Tokat Gaziosmanpaşa University Faculty of Dentistry. The evaluators were selected as subjective evaluators, each as a Dentist Specialist in the field of Prosthetic Dentistry, Research Assistant, a 5th year Dentistry student who completed the necessary success criteria in prosthetic clinical applications, and a 3rd year Dentistry student observing in the Prosthetic Dentistry Department. Five different dentolabial criteria were examined on the photographs. Measurements of incisor edge and lower lip parallelism, smile line, smile width, buccal corridor, interincisal line and midline variables were made with Adobe Photoshop CC 2021 program. The measurement results obtained and the subjective opinions of the evaluators were analyzed with IBM SPSS V23. Compliance was compared with the Kappa test. Analysis results are presented as frequency (percentage). Significance level was taken as p=0.05. Result: The compatibility of the dentolabial criteria determined in our study, the survey results of the evaluators and the computer measurements, and the compatibility of the evaluator groups among themselves were compared. Specialist physicians showed the highest agreement in terms of incisor slope and lower lip parallelism (k=0.394), laugh line (k=0.339), smile width (k=0.351), buccal corridor (k=0.148) criteria. The thirdyear students of Dentistry showed the highest agreement in the interincisal and midline criteria (k=0.183). Conclusions: In the evaluation of smile aesthetics, objective measurements and subjective opinions are generally parallel to each other. As the evaluators increased their experience in the field of Prosthetic Dentistry, they showed a more critical perspective in the evaluation of aesthetic appearance. Key Words: Aesthetic smile, smile perception, incisor edge, smile line, smile width, buccal corridor, midline