Original article
Comparison of Chinese and US orthodontists' averaged evaluations of “facial attractiveness” from end-of-treatment facial photographs

https://doi.org/10.1016/j.ajodo.2007.04.039Get rights and content

Introduction

This study continues our assessment of agreement and disagreement among 25 Chinese and 20 US orthodontists in the ranking for facial attractiveness of end-of-treatment photographs of randomly sampled growing Chinese and white orthodontic patients. The main aims of this article were to (1) measure the overall pattern of agreement between the mean rankings of US and Chinese orthodontists, and (2) measure the strength of agreement between the rankings of the US and Chinese orthodontists for each patient.

Methods

Each judge independently ranked standard clinical sets of profile, frontal, and frontal-smiling photographs of 43 US patients and 48 Chinese patients. For each patient, a separate mean rank was computed from the responses of each group of judges. Pearson correlations between the mean ranks of the 2 groups of judges were used to measure their overall agreement. Paired and unpaired t tests were used to measure the agreement between the judges of the 2 groups for each patient.

Results

The overall agreement between the mean rankings of the US and Chinese judges was very high. For the US patients, the correlation between the Chinese and US judges means was r = 0.92, P <0.0001. For the Chinese patients, the analogous value was r = 0.86, P <0.0001. Agreement between the 2 groups of judges concerning each patient was also generally strong. For two thirds of the patients, the mean ranks of the US and Chinese judges differed by less than 1 unit in a scale of 12. However, for 6 patients considered individually (5 Chinese and 1 US), the assessment of the 2 groups of judges was statistically significantly different at P values ranging from 0.02 to less than 0.0001, even after the Bonferroni correction.

Conclusions

These findings demonstrate that orthodontic clinicians can reliably identify and rank subtle differences between patients, and that differences between judges and between patients can be distinguished at a high level of statistical significance, given appropriate study designs. However, the reasons clinicians give for the differences in their judgments are more difficult to investigate and will require further study.

Section snippets

Material and methods

The data analyzed in this study are from the same sources as those of our previous article.16 The images ranked for attractiveness were standard end-of-treatment sets of facial photographs for 91 adolescent orthodontic patients. Each set included a profile, a full-face, and a full-face smiling image (Fig 1). In this study, we refer to the set of 3 images for each patient as a “triplet.” The patients were randomly selected from those who had been treated in the faculty orthodontic clinic of

Results

For each patient in the US and Chinese samples, the mean ranks among the 25 Chinese judges and the 20 US judges were calculated. For any patient, the range of possible ranks from any judge extended from 1 (least attractive) to 12 (most attractive). For each patient, the mean ranks of the 2 groups of judges are therefore expressed in terms of units that are 1/12th the range between most attractive and least attractive.

Our first task was to identify the overall pattern of agreement and

Discussion

In interpreting the findings of this study, it should be noted that the mean rank of each patient in his or her group of 9 to 12 patients has been used to designate that patient's relative attractiveness rank among the entire cohort of patients of the same ethnicity. We recognize that this procedure is not completely accurate, since the judges actually compared each patient directly with only the other members of the group of 9 to 12 patients to which he or she had been randomly assigned. If a

Conclusions

Several general conclusions can be drawn from the data in this article.

  • 1.

    The mean rank of the Chinese orthodontists was close to that of the US orthodontists for most patients. The average difference between the 2 means for individual patients was approximately 1 unit of a possible range of 11.

  • 2.

    The variability among the ranks assigned to each patient in each group of judges (measured by their standard deviations) tended to be larger than the differences between the mean ranks of the 2 groups of

References (26)

  • W.H. DeKock et al.

    The World Federation of Orthodontists: “bringing the world together”

    Am J Orthod Dentofacial Orthop

    (2000)
  • G. Rhodes

    The evolutionary psychology of facial beauty

    Annu Rev Psychol

    (2006)
  • T.R. Alley et al.

    Averaged faces are attractive, but very attractive faces are not average

    Psychol Sci

    (1991)

    • Cited by (0)

    Supported in part by NIH-NIDR grants DE07332 and DE08713, and the American Association of Orthodontists Foundation.

    The authors report no commercial, proprietary, or financial interest in the products or companies described in this article.

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    Copyright © 2009 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.