Finding things in everyday life that empower you to evaluate statistics or theorize estimates on a scenario has always been fun for my children and me. It becomes somewhat of a game, searching for certain attributes and data points to bring a story together. Sometimes it develops into a cost-benefit analysis of the carbon impact of a Kuerig Coffee maker versus a Breville One-touch. Other times it involves eating M&Ms as we discuss how many M&Ms are in the wall of storage containers at an M&M store. It's not a final thesis presented for a doctorate in economics but instead a personal exploration to get us closer to an answer, welcoming a more accurate way to estimate, or permission to investigate more in a subject. At the end of each economic adventure, we achieved our objective of knowing that our answer isn’t exactly right but we accept we are directionally correct.
Estimating can be a difficult concept for kids to understand and master. Many of them would rather just solve the problem or measure the item exactly—why bother estimating? - Weareteachers.com
At OpEmpathy, we introduced you to one when we considered the financial benefits of hand picking a 10-pack of Munchkins versus single counting ten of them at Dunkin. I have noticed that if I bring in these views and experiments routinely, it allows my family and myself to explore for answers that don’t exist. One we recently discussed was the option to have plastic braces to cosmetically align teeth versus stainless steel. How much melted stainless steel is displaced annually in the United States with the plastic option being available?
The impact of plastic braces on the stainless steel industry
When I was a kid, I didn’t have dental braces so this estimate was going to become personal. I had multiple attempts for straight teeth with stainless retainers but broke them so many times my dad gave up on the investment. I remember him saying something like, “Sorry kid, you will have to get your own sometime later in life if you want them. I can’t afford them.”
About three years ago, I was recommended to buy Invisalign because my dentist and myself notice some movements in my X-rays. This triggered with me the plastic option versus the stainless option I missed out on more than 30 years ago? How has the availability of a plastic retainer option and the ease of getting your teeth aligned influenced the stainless steel market? How much less stainless steel is produced in the melting process resulting from this option of a finished product? Let’s do the math.
It’s natural for the teeth to shift throughout life, according to the American Association of Orthodontists. Your teeth also undergo wear and tear due to a lifetime of chewing, grinding, and biting. - webmd.com
Understanding the weight
Humana references that ~4 million individuals in the United States wear braces at any given time. We are making an assumption here that 50% of people have plastic braces versus stainless braces right now. So that’s 2 million sets of braces per year that are stainless. Now for the weight of braces. I am not an orthodontist, so we were surprised to learn that there are different dimensions (e.g. round, square, rectangle) and grades. Additionally, sometimes titanium is used when individuals are allergic to nickel found in the applicable stainless. We did not know that. Additionally, sometimes wires get changed and diameters get changed as teeth move, yet sometimes they don’t. Back to the weight.
Dimensionally, we will assume that the average diameter is 0.4 mm and length averages around 200 mm total for a top and bottom set of braces. That comes to about 2 grams per set of braces. Let’s double it for all of the metal clips, repairs, and variability. So 4 grams per set of braces. 4 grams at 2 million people per year equates to about 9 Short-tons of stainless steel in the United States.
These assumptions indicate that the plastic solution displaces about 9 Short-tons of finished stainless steel in the form of 304, 316, or 17-4 martensitic. Yield this through all of the manufacturing process steps from raw material to 0.4 mm stainless wire at a rolled throughput yield of around 50%, this comes to about 18 tons. So we estimate that approximately 18 tons of stainless steel are displaced with a plastic solution within the United States each year.
Make estimates fun
In this one question, we were able to talk about short-tons versus long tons. We were able to build metaphors that allowed us to discuss what rolled-throughput yield. We were able to discuss the benefits of having different dimensions of stainless wire. We were able to conduct minor research and explore data points we were unaware of. We made estimating fun. We explored a random mystery.
As you are out walking around or driving down a road if a random thought comes into your head explore it. Introduce it to your children or think out loud as you go through the estimates. These questions to uncover are everywhere, and bringing some of the family along for the ride will open their eyes to solve the world’s problems versus just letting them pass by.