The Analysis of Facio-Dental Proportions to Determine the Width of Maxillary Anterior Teeth: A Clinical Study

Evaluation of the parameters related to the golden ratio in the teeth of individuals from different countries: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Golden proportion, golden percentage, and recurring esthetic dental (RED) proportion are parameters used in esthetic dentistry. However, a meta-analysis of studies evaluating these parameters in individuals from different countries is lacking.

PURPOSE

The purpose of this systematic review and meta-analysis was to determine and compare the golden ratio, golden percentage, and RED ratio values as seen in the maxillary anterior teeth of individuals from different countries.

MATERIAL AND METHODS

A systematic search was performed using PubMed/Medline, Google Scholar, and Web of Science to identify English and non-English language articles reporting the golden proportion, golden percentage, and RED proportion. The titles, full text, and abstracts were scanned by 2 investigators independently to identify articles that fulfilled the inclusion criteria. Using a meta-analysis software program, data extracted from each selected study were statistically combined using the random-effects model. Weighted mean differences, 95% confidence intervals, and heterogeneity were calculated for each measurement.

RESULTS

The search protocol resulted in a total of 752 articles, but only 26 articles fulfilling the inclusion criteria were included in the meta-analysis. While the sample size varied between 46 and 384 in the 26 analyzed studies, a total of 3786 individuals from 12 countries were evaluated. No similarity was found using the esthetic parameters determined in the populations to which the meta-analysis was applied.

CONCLUSIONS

Mathematical formulas did not provide consistent results that would allow for their use as a standardized guide for creating natural looking smiles. Rather, dental esthetic ratios should be set based on the racial and ethnic character of a population.

Maxillary Anterior Teeth Dimensions and Relative Width Proportions: A Narrative Literature Review

Predictable results in the aesthetic treatment of anterior teeth can be obtained by resorting to the concept of dental aesthetics and, in particular, defining the ideal tooth dimensions and proportions to obtain a harmonious smile. Considering the great variety of articles dealing with the topic, and the lack of updated reviews, this narrative literature review aims to evaluate current knowledge on anterior teeth dimensions and to verify the existence and the potential applications of the anterior teeth proportioning theories (Golden Proportion, Golden Percentage, RED Proportion, and Golden Rectangle). PubMed, Embase, Cochrane Library, and Google Scholar databases were comprehensively searched using different keywords and term combinations. The research includes articles published up to June 2023, no time limits were set, and only articles in English were included. Inclusion criteria comprehended reviews, clinical studies, and in-vitro studies. A total of 66 articles were selected. Two main topics were identified: "Anterior teeth dimensions", "Golden Proportions, Golden Percentage, RED Proportions, and Golden Rectangle". As far as tooth dimensions are concerned, different width ranges are recognized for men and women and for different ethnic groups. Perfectly symmetric contralateral elements are found in low percentages of subjects. The correlation between dental dimensions and facial parameters is not always present, and it strongly depends on the sample's ethnicity and gender. Ideal tooth proportions were only partially identified.