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Commentary on: Discriminative Thresholds in Facial Asymmetry: A Review of the Literature.

It is a pleasure to provide a commentary on this engaging and innovative review article.1 It is important at the outset, before delving into the crux of the article, to define what we mean by the type of studies reviewed in this article. Facial attractiveness research may be defined as the scientific study of facial beauty and physical attractiveness; the purpose is to find quantifiable evidence for the attractiveness of various facial parameters utilizing contemporary population survey preferences (using lay people, clinicians, and ideally patients as observers), rather than just relying on the subjective interpretations or observations made by artists or clinicians.2 Leonardo da Vinci (1452-1519) had perhaps the best eye for human beauty, in relation to both detail and understanding, but in terms of finding ideal facial proportions in his case for art and sculpture, he wrote: “make an effort to collect the good features from many beautiful faces, but let their beauty be confirmed rather by public renown than by your own judgement.”3 [Emphasis added] This is very important and is exactly what we do today in facial attractiveness research studies. The methods we employ were first described by the English artist William Hogarth (1697-1764).2,4 To find the “ideal” attractiveness of any object, Hogarth drew the object, and then proceeded to draw graded variations of the same image, varying ideally in only one respect. The individual images were then shown to members of the public who chose their favorite. This, in essence, is still what we do today. This innovative approach means that we may come closer to finding out why one image is preferred over another. In modern facial attractiveness research, the technique may be taken one step further: in addition to finding the most attractive image among a set of images, we may also gain an understanding of the range of normal variability in terms of observer acceptance; further still, we may find threshold values or “cutoff” points in terms of desire for surgery. In this review, the authors have concentrated on the threshold values of desire for surgery, which are extremely important, and which they have termed “discriminative thresholds,” but the ranges of normal variability for any facial parameter should not be ignored. Why is the approach of finding discriminative thresholds, as utilized by the authors in this article, useful? First, it provides data that may be utilized as guidelines (not rules, because clinical judgement will always be required, but only as a starting point) by surgeons when planning treatment; in this respect, it is vitally important to bear in mind the age, gender, and ethnicity (of both the images observed and the observers taking part in research), and of course cultural influences on perceptions of attractiveness. Such data and guidelines also may be particularly useful in communicating with patients, particularly when a patient’s concerns are excessive compared with a minimal facial asymmetry. This provides quantitative supportive data, which may be utilized to explain to the patient that his or her concern is excessive without inadvertently being offensive.