The Effect of Image Size on Ratings of Fluorosis Acceptability

Introduction: Numerous previous studies have aimed to determine whether fluorosis is perceived as an aesthetic problem. The methods of assessing this have varied, but higher fluorosis scores have been consistently associated with lower aesthetic ratings. Objectives: The purpose of this study was to determine whether the appearance and acceptability of tooth appearance would vary by the size of the image, and whether scoring for the opposite sex was significantly different from scoring for one's own. Methods: Seven laser-printed images of wet teeth were rated on an ordinal scale for four questions under standardized conditions. One image showed normal enamel, 5 showed fluorosis, and 1 demarcated white opacities not related to fluorosis. The study used a cross-over design - half of the subjects viewing small and half large images - on two occasions. The sequence of photographs was different between large and small sets but each set began with images of normal enamel or ‘Questionable fluorosis'. Results: There was no significant difference between the combined ratings over the two occasions for each group. There was no significant difference between the proportions of people who rated the appearance acceptable between the large and small images. There was no significant difference in the proportion of people happy with the appearance rated for the same versus the opposite sex. However, the results showed that less than half of the subjects rated demarcated opacities, or fluorosis more severe than Dean's ‘Very mild' as acceptable or not needing treatment to improve appearance. Dean's ‘Questionable Fluorosis' was consistently rated as the most attractive appearance and the one fewest people would want to improve on. Conclusion: The acceptability of tooth appearance declined with the increasing severity of fluorosis beyond Dean's ‘Questionable Fluorosis', and this result was not affected by the size of the image viewed.