During a dental check up, your dentist is calling out tooth numbers while the assistant charts it into the computer. Which teeth is what number? Wouldn't it be nice to know exactly which tooth they are talking about?
This is a guide for understanding the american teeth numbering system and how we chart teeth numbers. You'll be an expert at dental lingo by the time you finish reading this article. It'll be less confusing the next time you're in a dental chair because you'll understand precisely what your dentist is talking about.
Table of Contents:
Tooth numbering system
In the United States, we use the universal numbering system to correctly identify teeth. The adult teeth are numbered differently than the primary or milk teeth.
Adult teeth are numbered from 1 to 32.
Children's teeth are numbered using letters from A to T.
Therefore, your permanent teeth are classified using numbers while your deciduous teeth (baby teeth) uses alphabetical letters.
Alternative tooth numbering systems
Aside from the United States, every other country in the world uses the FDI Notation (FDI World Dental Federation notation) and that includes the World Health Organization. The numbering system for that notation is different from the universal system. Please be aware that we will be mostly covering the universal system.
There is another system, which is used mostly in the United Kingdom called the Palmer notation. It was actually named after an American dentist, Dr Corydon Palmer from Warren, Ohio.
How are teeth numbered
The full adult dentition is numbered from 1 to 32. Your top teeth are 1-16 while your bottom ones are 17-32.
How to count your own teeth in your mouth
If you have all of your wisdom teeth and did not remove any other teeth, you should have 32 teeth on average. You start counting with your upper right wisdom tooth.
Tooth 1 is the first back tooth on your upper right side.
Then you start counting towards the left: number 2, number 3, number 4, and etc.
The last tooth on the upper left side should be tooth 16.
Next you start with the first back tooth on the lower left side, which is tooth 17.
Then you start counting towards the right: number 18, number 19, and etc.
The last tooth on the lower right side should be tooth 32.
If you do NOT have all of your wisdom teeth because you had them removed, you would start counting with your upper right second molar.
The first back tooth on the upper right side would be tooth number 2.
Count towards the left and the last tooth on the upper left is number 15.
Next the bottom left back tooth would be number 18.
Count towards the right and the last tooth on the lower right is number 31.
How to count teeth on diagrams and x-rays
Counting teeth on odontograms and x-rays are different than in your mouth because you are counting based on the viewpoint of a dentist or oral healthcare professional. The charts, diagrams, and x-rays are practically labeled as if a dentist was looking into your mouth directly. What this means is that everything is reversed or flip-flopped.
The left side on the chart correlates with the right side of your mouth.
The right side on the chart correlates with the left side of your mouth.
On the diagram above, tooth 1 is on the left side of the chart but it is actually on the upper right side in your mouth. This is to demonstrate to you how charting the teeth is different from counting directly in the mouth.
The same principle applies to counting teeth on dental x-rays. The top tooth on the left side of the x-ray is tooth 1. The dental x-ray below is a panoramic of an adult human's full dentition of 32 teeth.
Teeth numbers and names
The tooth number gives you two pieces of information such as the name of it and also the location of it in your mouth.
Tooth 1 = Upper right wisdom tooth
Tooth 2 = Upper right second molar
Tooth 3 = Upper right first molar
Tooth 4 = Upper right second premolar
Tooth 5 = Upper right first premolar
Tooth 6 = Upper right canine
Tooth 7 = Upper right lateral incisor
Tooth 8 = Upper right central incisor
Tooth 9 = Upper left central incisor
Tooth 10 = Upper left lateral incisor
Tooth 11 = Upper left canine
Tooth 12 = Upper left first premolar
Tooth 13 = Upper left second premolar
Tooth 14 = Upper left first molar
Tooth 15 = Upper left second molar
Tooth 16 = Upper left wisdom tooth
Tooth 17 = Bottom left wisdom tooth
Tooth 18 = Bottom left second molar
Tooth 19 = Bottom left first molar
Tooth 20 = Bottom left second premolar
Tooth 21 = Bottom left first premolar
Tooth 22 = Bottom left canine
Tooth 23 = Bottom left lateral incisor
Tooth 24 = Bottom left central incisor
Tooth 25 = Bottom right central incisor
Tooth 26 = Bottom right lateral incisor
Tooth 27 = Bottom right canine
Tooth 28 = Bottom right first premolar
Tooth 29 = Bottom right second premolar
Tooth 30 = Bottom right first molar
Tooth 31 = Bottom right second molar
Tooth 32 = Bottom right wisdom tooth
Tooth number chart by quadrants
Your teeth are often charted and divided into quadrants because there is the same amount and type of teeth in each quadrant. There are four quadrants in your mouth.
Upper right - Teeth 1 through 8
Upper left - Teeth 9 through 16
Lower right - Teeth 17 through 24
Lower left - Teeth 25 through 32
There are 8 teeth in each quadrant and they each contain 4 types of teeth.
Three molars
Two premolars
One canine
Two incisors
When are quadrants used in dentistry?
The most common dental procedures, which uses quadrants instead of numbering would be deep teeth cleanings and gum surgery. Both of these treatments are usually performed on two quadrants at a time. This means that in order to complete the entire treatment, it would require two separate visits. There are exceptions for the deep cleanings because sometimes you may be able to do all of it in a single visit.
Teeth number chart by tooth names
This is a chart of the different tooth types and their respective number.
Molar teeth - Numbers 1-3, 14-19, 30-32
Bicuspid teeth - Numbers 3-4, 12-13, 20-21, 28-29
Canine teeth - Numbers 6, 11, 22, 27
Central incisor teeth - Numbers 8-9, 24-25
Lateral incisor teeth - Numbers 7, 10, 23, 26
Wisdom teeth - Numbers 1, 16, 17, 32
What numbers are wisdom teeth?
Well, there are 4 wisdom teeth in your mouth on average and they are numbers 1, 16, 17, and 32. There are exceptions because some people have more than 4 wisdom teeth!
Which teeth are the anterior teeth?
The anterior teeth are your front teeth and you have a set on the top and a set on the bottom. The top teeth are numbers 6 through 11 while the bottom ones are 22 through 27.
Which teeth are the posterior teeth?
The posterior are all of the teeth in the back of your mouth. There are more posterior teeth than anterior teeth.
Takeaway
Here in the US, we use the universal tooth numbering system so the teeth are numbered from 1 to 32. Other parts of the world uses a different system so they would be numbered differently. This guide is for understanding the american way and would be helpful to you if you visited a dentist in the US.
This way you would understand which tooth in your mouth needs a cavity filling and which tooth should be flossed or brushed more! If you have any further questions, please don't hesitate to schedule a dental check up with our dental office.
This article was written by Dr David Chen, a cosmetic dentist in long island city.
