Assessment of dental appearance following changes in incisor proportions

This study aimed to evaluate the assessment of attractiveness of standardized changes in incisor proportions. Two original photographs, showing the maxillary anterior teeth in the frame of a smile, were computer-manipulated. From the so-produced symmetrical 'golden standard' images, two sets were constructed. Each set contained one golden standard image and seven images with different standardized changes concerning (i) width-to-length ratios of the central incisors (60-96%) and (ii) tooth-to-tooth proportions between the widths of lateral and central incisors (43-87%). The judges, consisting of three groups of individuals (24 dentists, 24 medical students, and 179 patients), ranked each photo set for attractiveness on a visual analogue scale. The width-to-length ratios were assessed as most attractive within a range of 75-85% (medical students, patients) or 75-80% (dentists), respectively. The tooth-to-tooth proportions showed the best results concerning attractive appearance within a range of 50-74% (medical students, patients) or 56-68% (dentists), respectively. No significant differences between the participant groups were found except for some extreme variations. It was concluded that a most attractive 'golden range' could be identified for both the width-to-length ratios and the tooth-to-tooth proportions of the maxillary incisors.