Evaluation of maxillary anterior teeth width: A systematic review

Abstract

Statement of problem: Estimating the width of the maxillary anterior teeth when creating an esthetic smile can be challenging. Valid metrics to assist in this process are needed.

Purpose: The purpose of this systematic review was to evaluate the validity of interalar distance and inner canthal distance with the golden proportion, golden mean, and recurring esthetic dental proportion in predicting intercanine distance and the combined width of central incisors to potentially provide a guide for tooth restoration.

Material and methods: A literature search was conducted using PubMed, Medline, Google Scholar, EMBASE, CNKI, Web of Science, and the Cochrane Collaboration, identifying English- and non-English-language articles reporting on interalar width, inner canthal width, and maxillary anterior tooth width. Additional studies were identified by searching reference lists of the articles identified. Only studies that fulfilled inclusion criteria were included. Two examiners independently performed the literature search and data extraction. 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 strategy resulted in a total of 282 articles, but only 41 articles fulfilling the inclusion criteria were included in the meta-analysis. The interalar distance was found to be significantly larger than intercanine distance, and the inner canthal distance was found to be substantially smaller than the intercanine distance. When predicting the central incisors combined width by interalar distance, both the golden proportion and golden mean predicted value were larger than the combined width of the central incisors. Only the recurring esthetic dental proportion (70%) predicted value showed no significant difference from the combined width of central incisors. When predicting the central incisors combined width by inner canthal distance, the golden proportion predicted value was larger than the combined width of central incisors, whereas both the golden mean and recurring esthetic dental proportion (70%) predicted value were found to be significantly smaller than the combined width of central incisors.

Conclusions: By analyzing the data from the literature, only the recurring esthetic dental proportion (70%) with interalar distance could be an accurate method for predicting the combined width of central incisors. Neither interalar distance nor inner canthal distance could directly be used to predict the intercanine distance.