Evaluation of "Golden Proportion" in Saudi individuals with natural smiles

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.

Analysis of recurrent esthetic dental proportion of natural maxillary anterior teeth: A systematic review

STATEMENT OF PROBLEM

The recurrent esthetic dental (RED) proportion has been a benchmark for the rehabilitation of the maxillary anterior teeth of North American patients. While it has been evaluated in other populations, the global application of RED proportions in the rehabilitation of maxillary anterior teeth is unclear.

PURPOSE

The purpose of this systematic review was to examine the existing evidence on dental proportion to evaluate the existence of RED proportions in the esthetic smile in different geographic regions.

MATERIAL AND METHODS

A systematic search was conducted by reviewing different databases. The focused question was "Does RED proportion exist in esthetically pleasing smiles in different populations around the world?" The search included articles with a combination of MeSH keywords based on dental proportion from January 2000 to July 2020. The titles and abstracts were identified by using a search protocol. Full text of the articles was independently evaluated. The systematic review was modified to summarize the relevant data. The general characteristics, outcomes, and quality of studies were reviewed and analyzed systematically.

RESULTS

Seventeen studies were selected from the reviewed articles. Three studies were conducted in Europe, 10 in South Asia, and 4 in Western Asia. Eleven studies found that the mean perceived ratio of anterior teeth was not constant when progressing distally. Five studies reported that the ratio was constant in a small percentage of their populations, and 1 suggested that the ratio was constant if it remains between 60% and 80%. The central-to-LI and Ca-to-LI proportion values were not constant. Overall, the Ca-to-LI proportion values were higher than the central-to-LI proportions.

CONCLUSIONS

RED proportions were not found in the successive widths of maxillary anterior teeth among the reviewed data from different geographic regions. RED proportions are not the only standard for restoring esthetic smiles worldwide, and anterior tooth proportions differ among populations based on their race and ethnicity.

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.

The assessment of Golden and Red Proportions among a North-African population

INTRODUCTION

The constant increase of both esthetic demands and advancement in materials and technologies have led to the development of guidelines to achieve optimal aesthetic results. These tools are useful to predict the teeth proportion and dimensions. Golden and Red proportion are the most described theories.

AIM

of present study was to evaluate the existence of both Golden and Red proportion in the maxillary anterior teeth among a North-African population.

METHODS

This was an observational study performed at the Fixed Prosthetic department of the dental clinic of Monastir, Tunisia. The study included participants with full intact anterior dentition. Those with diastema or teeth crowding were excluded. For each one, an alginate impression was done. Measures were, including the perceived width and length, have been taken on casts using digital caliper. Width ratios of maxillary lateral incisor to maxillary central incisor and lateral incisor to canine were calculated.

RESULTS

The study included 100 Tunisian participants including 97 females and 21 males. The maxillary central incisors were the largest (8.60±0.58mm) and the longest (99.71±1.14mm). The ratio was 0.89±0.09mm. Anterior teeth dimensions were not statistically not different between males and females. Significant differences were observed between calculated ratios with GP and to each other's. (p=0).

CONCLUSIONS

Either GP nor RP is applicable amongst the Tunisian Population.

Anterior Upper Teeth Golden Proportion Analysis with Millimetric Templates: An Invention Developed at Londrina State University

In order to achieve aesthetic and harmonious smile results, the use of anterior upper teeth golden proportion concepts represents reliable and scientific based guidelines. However, measuring, recording and analysing teeth and smiles biometric values proves to be a clinical and laboratory routine chalenge, once it is time consuming and demands additional especific math calculus or formulas. The aim of this paper is present an invention, “anterior upper teeth golden proportion millimetric templates,” a set of instruments fabricated in order to achieve precise and fast millimetric measures, once they present predefined geometrical drawings and diagrams. Currently, when planning aesthetic tooth size modifications treatments, tools are used as pachymeters, dry edge compass, or some softwares. Most of times this strategy relies on professional expertise and intuiton, which shows to be limitating factors with the need of trial-and-error training and an accurate critical and artistic sense. Unfortunately, this is not inherent to all professionals, especially undergraduate dental school students. Thus, the templates bring differentials and advantages, being versatile and convenient, allowing countless clinical and laboratory uses, even over a cellphone or a computer screen. An excellent diagnostic aid providing ideal teeth proportions and positioning, increasing the chances of success in dental treatment planning.

Assessment of Golden Proportion among Natural Maxillary Anterior Teeth of Global Population: A Systematic Review

The purpose of this systematic review was to analyze studies, identify the existence of golden proportion between the perceived widths of the maxillary anterior teeth among the different geographical populations, and evaluate the range of dental proportion that exists regionally. An electronic search was conducted using PubMed, Medline, EMBASE, Scopus, Science Direct, Web of Science, and the Cochrane Library. The focused question was, “Does golden proportion exist in natural, aesthetically pleasing smiles among different populations around the world?” The search conducted included studies from January 2000 to September 2020, identifying articles in English with the specific combination of MeSH and other related terms. The title search yielded eight hundred and ninety-eight articles, and seventy-five articles were selected for full-text analysis. However, only fifty-two full-text articles were included in the systematic review. The mean predicted dental ratios were either larger or smaller than the successive widths of maxillary natural anterior teeth. Golden proportions were not found consistently among anterior teeth in different populations observed in the systematic review. The golden proportion is still a useful tool for the reconstruction of lost or damaged anterior tooth widths; however, it is not the only standard for restoring esthetic smiles worldwide, and anterior tooth proportions differ among populations based on their geographic, ethnic, and racial background. Moreover, consideration should also be given to an individual’s dentofacial variations in restoring anterior teeth.

Mathematical Tooth Proportions: A Systematic Review

PURPOSE

The aim of this systematic review was to evaluate and compare three commonly used proportions that include the golden proportion, golden percentage, and Recurring Esthetic Dental (RED) proportion to identify which of the mathematical formulas, if any, can be used to provide predictable and repeatable esthetic clinical outcomes.

METHODS

A comprehensive search of electronic databases that included EBSCO, ProQuest, SCOPUS, Science Direct, Wiley, Google Scholar and PubMed was conducted using the terms: "golden proportion," "golden percentage," and "Recurring Esthetic Dental (RED) proportions" alone or in concurrence with one or both ensuing terms: "tooth proportions" and "esthetic tooth proportions." In addition, the following journals were hand searched for relevant articles: Journal of Prosthodontics, Journal of Prosthetic Dentistry and Journal of Esthetic and Restorative Dentistry. Related citations were also considered.

RESULTS

Tooth proportions varied substantially in the natural dentition. No studies revealed findings that supported the use of one mathematical formula to predict esthetic success. The golden proportion is present between the central to lateral incisor in some cases, but rarely between the lateral incisor and the canine. When compared to the other proportions, the golden percentage provided better starting points for tooth shape and size, but only when values were adjusted to consider other factors such as ethnicity and/or facial proportions.

CONCLUSION

Mathematical formulas did not provide consistent results that would allow for their use as a standardized guide for esthetically pleasing smiles. Although the golden percentage may be a good starting point if the percentages are adjusted on a case-by-case basis, generalized esthetic ideals cannot be determined by a mathematical formula and are open to interpretation by both the clinician and the patient.

Evaluation of golden percentage in natural maxillary anterior teeth width: A systematic review

STATEMENT OF PROBLEM

The color and form of teeth are 2 of the 3 main determinants of success in an esthetic restoration; the third is dental proportion. A recent systematic review of the literature devoted to the evaluation of dental proportion is lacking.

PURPOSE

The purpose of this systematic review was to investigate the quality and outcome of studies into maxillary anterior tooth proportion and to determine whether dental proportion ratios based on different geographic regions are appropriate.

MATERIAL AND METHODS

An electronic search was conducted using PubMed, MEDLINE, Google Scholar, Embase, Scopus, Cochrane Library, Web of Science, and Science Direct databases. English-language articles reporting with the specific combination of medical subject heading (MeSH) key words were analyzed by 2 investigators. The titles, full text, and abstracts were scanned by investigators independently to identify articles that fulfilled the inclusion criteria. The general characteristics, outcomes, and quality of each study were reviewed and analyzed systematically.

RESULTS

The search plan resulted in a total of 73 articles until September 2020; of which, 16 articles fulfilling the inclusion criteria were selected. The geographic distribution of the selected article revealed 12 articles from Asia, 2 from Continental Europe, and 2 from the United Kingdom. Golden percentage values of 25%, 15%, and 10% for central, lateral incisor, and canine teeth were not found. The mean predicted dental percentage was either larger or smaller than the successive widths of maxillary natural anterior teeth.

CONCLUSIONS

The golden percentage could not be used to formulate a smile design. Rather, the dental ratios should be set on a racial and ethnic basis for a population.

Golden Standard and Golden Proportion of Maxillary Anterior Teeth Among Saudi Population in Makkah

Background

Maxillary anterior teeth are important in achieving optimum aesthetics, Different methods are used to calculate their dimension: as golden standard (GS) to measure Width/Height (W/H) of anterior teeth and Golden Proportion (GP) to measure their perceived widths. Researchers had reported on GS and GP in different populations.

Objectives

The aim of the present study is to evaluate the occurrence of GS and GP of maxillary anterior teeth among the Saudi population in Makkah.

Materials and Methods

A total of 384 participants (2304 teeth) were included in this study; photographs were taken by using a digital camera at a fixed distance and saved on a personal computer; the perceived mesio-distal widths and occluso-gingival heights of the maxillary anterior teeth were measured; GS was calculated from W/H of upper central incisors (W11/H11 and W21/H21); and GP was calculated from width of canines/laterals (W13/W12 and W23/W22) and laterals/centrals (W12/W11 and W22/W21). The normal range of GS was considered between 75% and 85%, whereas the normal range of GP was considered between 55% and 65%. Data were analyzed by using suitable statistical tests, and p-value ≤ 0.05 was considered statistically significant. Both GS and GP were compared in relation to gender, race, and shape of the face.

Results

There were 43% of GS ratios, 14% of GP of canines/laterals, and 34% of GP ratios of laterals/centrals that were within the normal range. There were no significant differences between GS of males and females (p=0.512) as well as among different races (0.137), whereas there were significant differences among different face shapes (p=0.001). For GP of canines/laterals, there were significant differences between males and females (p=0.000), different races (p=0.000), and different face shapes (p=0.001). For GP of laterals/centrals; there were no significant differences between males and females (p=0.216) whereas there were significant differences among different races (p=0.000) and different face shapes (p=0.007).

Conclusion

The GS was 85% among the Saudi population in Makkah and it was more prevalent than other golden measures. The GP was 77.5 for canines/laterals and 65.8 for laterals/centrals, and their frequencies were very low. Personal characteristics and dento-facial specifications should be considered to obtain maximum aesthetics.

Analysis of dental esthetic proportions in a Spanish population sample

PURPOSE

The present study aimed to analyze in a Spanish population sample the compliance of the anterior maxillary teeth to the dental esthetic proportions described in the literature.

METHODS

Photographs of the smiles of 78 individuals were calibrated and digitally analyzed considering the following proportions: golden proportion (GP), recurring esthetic dental (RED), golden percentage (GPG), Preston's proportion and Modified golden percentage (MGPG). For statistical analysis, the t-test of an independent sample was applied, and compliance percentages for each standard were recorded.

RESULTS

The existence of RED 70% or 80% has not been registered. The percentages of compliance with GP were within a range between 0% and 16%. The mean tooth width ratios were adjusted to the values described by Preston (P > 0.05), but the compliance percentages were low (3.33-25%). GPG only presented high percentages of compliance in the lateral incisors (53.33-62.5%). MGPG showed the highest percentages of compliance (50-68%).

CONCLUSION

After analyzing a Spanish population sample using smile photographs for the first time, GP, RED, GPG and Preston's proportion standards are not fulfilled and therefore, not suitable for treatments that seek a smile that reproduces natural principles. However, the values designated by MGPG with a deviation of ±1% are largely applicable for treatments that aim for a natural smile.