Tooth Number Chart: Universal Numbering System
U.S. dentists number adult teeth 1 to 32, from upper right to upper left, then lower left to lower right. Baby teeth are lettered A to T.
Tooth number chart (adult)
U.S. dentists use the Universal system: 1 to 32, starting at the upper right wisdom tooth. "Right" means the patient's right.
Upper right central incisor · ISO number 11
| U.S. number | Tooth | ISO number |
|---|---|---|
| 1 | Upper right third molar (wisdom tooth) | 18 |
| 2 | Upper right second molar | 17 |
| 3 | Upper right first molar | 16 |
| 4 | Upper right second premolar | 15 |
| 5 | Upper right first premolar | 14 |
| 6 | Upper right canine | 13 |
| 7 | Upper right lateral incisor | 12 |
| 8 | Upper right central incisor | 11 |
| 9 | Upper left central incisor | 21 |
| 10 | Upper left lateral incisor | 22 |
| 11 | Upper left canine | 23 |
| 12 | Upper left first premolar | 24 |
| 13 | Upper left second premolar | 25 |
| 14 | Upper left first molar | 26 |
| 15 | Upper left second molar | 27 |
| 16 | Upper left third molar (wisdom tooth) | 28 |
| 17 | Lower left third molar (wisdom tooth) | 38 |
| 18 | Lower left second molar | 37 |
| 19 | Lower left first molar | 36 |
| 20 | Lower left second premolar | 35 |
| 21 | Lower left first premolar | 34 |
| 22 | Lower left canine | 33 |
| 23 | Lower left lateral incisor | 32 |
| 24 | Lower left central incisor | 31 |
| 25 | Lower right central incisor | 41 |
| 26 | Lower right lateral incisor | 42 |
| 27 | Lower right canine | 43 |
| 28 | Lower right first premolar | 44 |
| 29 | Lower right second premolar | 45 |
| 30 | Lower right first molar | 46 |
| 31 | Lower right second molar | 47 |
| 32 | Lower right third molar (wisdom tooth) | 48 |
In the U.S., dentists number adult teeth 1 to 32. Tooth 1 is your upper right wisdom tooth. The count runs across the top to tooth 16, your upper left wisdom tooth, then drops to tooth 17, your lower left wisdom tooth, and runs back to tooth 32, your lower right wisdom tooth. This is the ADA's Universal Tooth Designation System, which the American Dental Association says is the most commonly used system among dental professionals in America. Use the chart above to look up any tooth by its number.
All 32 adult teeth
| Upper right | Upper left | Lower left | Lower right |
|---|---|---|---|
| 1 third molar (wisdom) | 9 central incisor | 17 third molar (wisdom) | 25 central incisor |
| 2 second molar | 10 lateral incisor | 18 second molar | 26 lateral incisor |
| 3 first molar | 11 canine | 19 first molar | 27 canine |
| 4 second premolar | 12 first premolar | 20 second premolar | 28 first premolar |
| 5 first premolar | 13 second premolar | 21 first premolar | 29 second premolar |
| 6 canine | 14 first molar | 22 canine | 30 first molar |
| 7 lateral incisor | 15 second molar | 23 lateral incisor | 31 second molar |
| 8 central incisor | 16 third molar (wisdom) | 24 central incisor | 32 third molar (wisdom) |
"Right" and "left" mean your right and left, not the dentist's. Most adults have eight incisors, four canines, eight premolars and 12 molars. Your dentist still assigns a number to a missing tooth, so if your wisdom teeth are gone, your teeth still run from 2 to 15 and from 18 to 31.
Baby teeth
Children's teeth use letters, A to T, beginning with the upper right molar. Most children have 20 primary teeth, and they erupt between about 4 months and 6 years of age.
Reading a treatment plan from abroad
Most other countries use a different method. In the ISO system, the first digit is the section of the mouth and the second is the tooth, counting back from the middle. So the ADA's value set lists tooth 1 as ISO 18, tooth 9 as ISO 21, tooth 17 as ISO 38 and tooth 32 as ISO 48. A Mexican or Turkish plan may use these two-digit numbers, so "tooth 14" could mean your upper left first molar in the U.S. and your upper right first premolar abroad. Before you agree to treatment, ask the clinic to use tooth names too.
| Universal | ISO | Tooth |
|---|---|---|
| 3 | 16 | Upper right first molar |
| 8 | 11 | Upper right central incisor |
| 14 | 26 | Upper left first molar |
| 19 | 36 | Lower left first molar |
| 30 | 46 | Lower right first molar |
Keep a copy of your own chart when you travel. Ask your U.S. dentist to mark existing crowns, fillings and missing teeth before you go.
Why tooth numbers matter for your wallet
- A U.S. claim needs tooth numbers. The ADA's claim form instructions use this system.
- If you use an HSA, ask for a receipt listing tooth numbers and treatments. See HSA and dental work in Mexico.
- Veneer sets are usually counted across the front teeth, so ask which numbers are included. See veneers in Mexico.
Our tooth number guide has more on the other numbering systems.
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Frequently asked questions
What is tooth number 14?
In the Universal system, it's your upper left first molar. In the ISO system used by most other countries, 14 is an upper right first premolar.
Which teeth are wisdom teeth?
Teeth 1, 16, 17 and 32 in the Universal system.
Do you still count missing teeth?
Yes. Cleveland Clinic says dentists assign numbers to missing teeth, so the numbering doesn't shift.
What numbers are the front teeth?
Your top two front teeth are 8 and 9. Your bottom two front teeth are 24 and 25.
How are baby teeth numbered?
With letters A to T, beginning with the upper right molar.
Sources
- Universal Tooth Designation System Value Set, Version 1, August 2022 — American Dental Association
- Teeth: Anatomy, Types, Function and Care — Cleveland Clinic
- ADA Dental Claim Form Completion Instructions — American Dental Association