The Measure of Pearly Whites


By The Metric Maven

Mini Bulldog Edition

One day when I was visiting my dentist, I took note of a procedure whose details I had ignored for many years. My dental hygienist had me wait a moment while she found a person to help her. In this age of computerized toasters, the assisting woman appeared with a clipboard. I was reclined and expect this woman sat down in a chair located behind me. The hygienist then began to read off a series of integers, two, two, three, four, two, two, two, three, three,….  It rather reminded me of the number stations that existed (probably still do) on short wave radios. One can tune into them and  listen to what is thought to be some code or cipher meant for some manner of operative.

I thought about it for a moment, and then asked “what are those numbers?”

“They’re pocket measurements of your teeth.”

Predictably I asked “are those values in millimeters?”

“Yes, millimeters.”

She was reading off the values at an astounding pace and the woman with the clipboard behind me was writing down the values. I then had another mystery on my hands.

“How on Earth are you measuring the values so quickly?”

The hygienist replied “oh, the periodontal probe is striped with one millimeter graduations.” She then showed me the probe and I could clearly see the one millimeter dark and light alternating stripes.

My dentist appeared and asked for the results compared with last time. I was rather pleased when she looked at the data and said with surprise “the numbers are all better?”

“Yes, better” the hygienist confirmed.

Unable to contain myself I blurted out “how is this determined from the data?”

To my chagrin, the trio all pointed to the rather large poster in front of me at the end of the dental chair just beyond my feet:


The chart has an image of the periodontal probe I was shown with its graduated dark and light bands. It has a chart, in millimeters, of the depths that are considered healthy in green (1-3 mm), yellow for a depth that will illicit concern (4 mm), and red for a value of 5 mm and beyond.

The simplicity and ease of this measurement had an elegant satisfying feeling. I wish I encountered more situations like this in the US.

If you liked this essay and wish to support the work of The Metric Maven, please visit his Patreon Page


The Metric Maven has published a new book titled The Dimensions of The Cosmos. It examines the basic quantities of the world from yocto to Yotta with a mixture of scientific anecdotes and may be purchased here.

5 thoughts on “The Measure of Pearly Whites

  1. Good article, but couldn’t you have found a newer dental floss picture to go with the positive tone of the article? The sample in my “swag bag” is marked 4 m (4,3 yd) and the one I buy 43.6 yd (40 m). Both FPLA compliant, unlike the one that looks like it is leftover from 1960.

  2. I had a 7 mm pocket, down to 5 mm last visit. During a root canal, the dentist called for a 25 mm file. Told me I had very long (Russian roll on the R) roots.

  3. Definitely not Frank’s dental floss. Not waxed and not from Montana.

  4. Wrt dental floss, I will buy only an SI standardized one. Thus, the Oral-B “complete”, which is marked “50 m (54.6 yd/vg)”, which is the way it should be. (BTW, what in the world is that “vg”??)

    • I am assuming French for yard. I have one package that includes it (sample from my dentist) and other markings on the package are bilingual, English and French, and cites manufacturer’s locations in Cincinnati and Toronto. However, I don’t know the word from which the symbol is derived.

Comments are closed.