# The Golden Proportion and Its Application to Dental Aesthetics

The Golden Proportion or Golden Ratio is a mathematical relationship that the ancient Greeks believed to represent the width to height ratio of everything in nature, i.e. the width to height of a butterfly wing, the width to height of a leaf. In 1976 it was introduced into dentistry in a prestigious journal which attracted significant attention. Beginning in 2008 I have periodocially googled “golden proportion dentistry”. In 2008 I received 450 hits. Last year I had 340,000 hits. Clearly dentists are using this ratio to create the widths of teeth when making smile makeovers and in enormous numbers. I must admit that when I first heard of this magical ratio that dictated everything in nature I was excited. I had an opportunity to make the front six teeth for a patient and asked my ceramist technician to use the Golden Ratio. My request was met with silence which said to me that he did not approve; so I asked him if he did not like the idea. He responded,”Yes”. I asked, “Why?” and again heard silence. So I asked if he thought it led to ugly teeth, and he said he did. Well, something deep down in my mind had been stirred, and I set out to prove him wrong. I wanted this magical idea to be true as does all those other dentists in the world which is quite interesting in that dentists pride themselves on “Evidence based research”.

I first went to the internet and got a thorough understanding of the Golden Proportion and all its various uses. I learned how to express in as line segments, as a arithmetic progression and as a geometric spiral. I then measured 100 samples of orthodontically corrected teeth, all which represented beautiful smiles. I compared the smiles to the Golden Proportion and found it to be accurate only 19% of the time which I found very disappointing. I went to the library of the American Dental Association which at the time had the world’s largest collection of dental literature. I found seven studies conducted in six different countries. All the studies agreed that the Golden Proportion when used to determine the widths of anterior teeth led to flawed and unnatural results and should not be used in dentistry. I found another study where the researcher compared the Golden Ratio to naturally occuring tooth widths and found it to apply 17% of the time which was similar to my conclusion. I then took a photograph of a smile that precisely represented the average widths of anterior teeth and artificially on my computer modified the relative widths of the six anterior teeth. The result were unnaturally wide central incisors and narrow cuspids.

My conclusion was, to my disappointment, that my technician was absolutely correct. In hindsight there is no evidence supporting the use of the Golden Proportion in dentistry. In fact all the evidence that I found in the literature agreed, 100%, that its use is flawed and should not be used. Nevertheless dentists in ever increasing numbers are applying its relationship when making smiles and getting unnaturally wide front teeth. I have presented my evidence to several dental societies, yet dentists who attended my lectures still insist on its use. I find this very interesting in consideration of how we dentists insist on evidence for our decisions but make an exception for this concept only because we so want to believe in magic.