Sir, the authors of The influence of maxillary central incisor height-to-width ratio on perceived smile aesthetics1 are to be complimented on the ingenuity of this study and the beautiful pictures illustrating the variations of the length of the central incisor in relation to the width. This subject has been studied in great depth over the years, to find the optimum aesthetic ratio for length of central incisors.

With regard to the study, the authors clearly illustrate that the optimum ratio of a single incisor is an 80% to 82% ratio but what they didn't say was that this is the width of the two incisors together as in Figure 1.

Figure 1
figure 1

The Golden Proportion rectangle

Full size image

As a pair they fit perfectly in the Golden Proportion rectangle (Fig. 1).

1 is to 1.618

As 100 is to 160

160 = 2 × 80

This relationship was described simultaneously by both Stephen Marquardt of the USA and Win Senior of Manchester and was included in my article in Aesthetic Dentistry May 2011 (volume 5, number 3, page 25, diagram 14). Also to be found on my website, www.goldenmeangauge.co.uk/dental.htm.

The two central incisors together have the strongest influence on the aesthetics of the smile. It is most unusual to look at the length-to-width ratio of a single incisor, because they are naturally seen and evaluated as a pair. Similarly, one never looks at one eye, but always gets an impression of the two eyes, together, unless of course one deliberately wants to look at one eye or one central incisor.

The Golden Proportion is so often seen in the beauty of nature; why should we not expect to see it in the beauty of natural teeth? In this respect, I find myself in total agreement with Mr P. Erridge's response.2