Preferences of Lay Persons and Dental Professionals Regarding the Recurring Esthetic Dental Proportion

This study evaluated the preferences of dental professionals and lay persons with respect to the Recurring Esthetic Dental (RED) Proportion, an objective mathematical tool used in treatment planning the "apparent" widths of maxillary anterior teeth.

Stock dentofacial and facial images of a prototypical smiling male and female were digitally altered to demonstrate five different RED proportion relationships (0.62, 0.65, 0.70, 0.75, and 0.80). Four sets of the five altered images were presented to dental professionals and lay persons using a web-based survey site. The professional group included dentists and dental laboratory technicians. The lay group included anyone without previous dental education or experience. Study participants were asked to rank each series from most to least esthetic and their preferences were extracted from the data.

Preference data from the five RED proportion relationships was consolidated into two categories: a narrow group including 0.62, 0.65, and 0.70 and a broad group including 0.75 and 0.80. Analysis shows that the level of professional training or experience does not play a significant role in the RED proportion preferences of study participants. Only in the prototypical male facial views was there any significant difference between professional and lay groups. For that view, a greater percentage of the layperson group preferred the narrow RED proportions. However, for the male dentofacial views that difference disappeared and both participant groups showed a slight preference for the broad proportion category. This may be due to the traditional esthetic stereotype for males to have broader, more vigorous appearing anterior teeth. For the prototypical female images, all participants expressed a clear, statistically significant preference for the narrower RED proportions in both full face and close up views.

Based on the results above, dental professionals who are developing a treatment plan should attempt to utilize a RED proportion ≤ 0.70 for both male and female patients.

The RED proportion is an objective numeric tool for relating the apparent widths of maxillary anterior teeth. It may be used by dental professionals to help diagnose and develop an optimal esthetic treatment plan. This paper offers insight into whether there are specific RED proportions that are preferred, whether there is a difference in preference when considering the male or female smile and whether professional educational training changes those preferences.