Comprehending the Dentist’s Plan: Tooth Number Chart

We cannot understand God’s plan, but we sure can understand the first step of dentist’s plan. Though it’s not as easy as it sounds.

Sitting on a dental chair, listening to the words of the dentist and the assistant, is no joke. It can cause anxiety or confusion, especially if you cannot understand what numbers they are talking about. What kind of tooth is tooth 13? By the end of this article, you’ll know the numbers assigned to each tooth so that the next time you hear a dentist talking about numbers, you’ll know which tooth he is referring to.

Understanding Quadrants

In the world of dental professionals, your mouth is divided into four quadrants. These are;

  • Upper right quadrant
  • Lower right quadrant
  • Upper left quadrant
  • Lower left quadrant

Each quadrant starts from the front incisors to the last molar teeth. There are different numbering systems used in different parts of the world. These numbering systems label quadrants in their own way.

Dentist’s Numbering System

The three most commonly used numbering systems worldwide are the FDI system, the Universal numbering system, and the Palmer notation system.

· FDI Numbering System:

This numbering system is widely used in Canada and is recommended by World Health Organisation (WHO). It consists of 2-digit numbers, the first being the quadrant and the second being the tooth. For an adult’s teeth, the quadrants have the following numbers;

  • Upper right quadrant – 1
  • Upper left quadrant – 2
  • Lower left quadrant – 3
  • Lower right quadrant – 4

For ease of learning, imagine yourself as a dentist examining a patient. Starting from the left side of the patient, examining the mouth in the clockwise direction, all the numbers fall in place systematically.

Like quadrants, individual teeth are also assigned a set of numbers. In the case of an adult, these are;

  • Central Incisors – 1
  • Lateral Incisors – 2
  • Canine (Cuspids) – 3
  • First Premolar – 4
  • Second Premolar – 5
  • First Molar – 6
  • Second Molar – 7
  • Third Molar – 8

Now let’s talk with an example. If we say tooth number 13 is the problematic one, we are referring to the Upper right canine. Similarly, if we say tooth number 24, we’re referring to the Upper left second premolar.

In the case of primary teeth, the method remains the same; only the numbers are changed. Instead of 1,2,3,4 quadrants are numbered as 4,5,6,7, and the numbers of the individual tooth are from 1 to 5 (4 and 5 being the 1st and 2nd molar). For example, tooth 63 means Upper left canine.

· Universal Numbering System:

This system is widely used in the United States of America (USA). This system is also in the clockwise direction, but different numbers are assigned to different teeth this time. The use of “hashtag” before each number sets them apart from other numbering systems.

Upper Arch (Right Side)

Upper Arch (Left Side)

Lower Arch (Left Side)

Lower Arch (Right Side)

Third molar #1

Central incisor #9

Third molar #17

Central incisor #25

Second molar #2

Lateral incisor #10

Second molar #18

Lateral incisor #26

First molar #3

Canine #11

First molar #19

Canine #27

Second premolar #4

First premolar #12

Second premolar #20

First premolar #28

First premolar #5

Second premolar #13

First premolar #21

Second premolar #29

Canine #6

First molar #14

Canine #22

First molar #30

Lateral incisor #7

Second molar #15

Lateral incisor #23

Second molar #31

Central incisor #8

Third molar #16

Central incisor #24

Third molar #32


The above table represents the permanent dentition. For primary teeth, numbers are replaced by alphabets. The chart for pediatric teeth will be as follows;

Upper Arch (Right Side)

Upper Arch (Left Side)

Lower Arch (Left Side)

Lower Arch (Right Side)

Second molar A

Central incisor F

Second molar K

Central incisor P

First molar B

Lateral incisor G

First molar L

Lateral incisor Q

Canine C

Canine H

Canine M

Canine R

Lateral incisor D

First molar I

Lateral incisor N

First molar S

Central incisor E

Second molar J

Central incisor O

Second molar T

Revision Exercise

Now that we know the dental numbering system, let’s do a set of quick questions to revise everything;

  • Wisdom teeth are the most difficult to clean with a manual toothbrush, but using an electric toothbrush can help. According to the FDI system, what numbers are assigned to wisdom teeth (third molars).
  • Dental plaque is a house of bacteria and is a root cause of gum diseases. Plaque readily accumulates on the lingual surfaces of teeth #22 to #27 and can be washed away with smart toothbrushes. According to the universal numbering system, mention the names of these teeth.
  • Tooth number 13 is the longest tooth, so its hygiene needs to be maintained regularly. What tooth is tooth number 13 according to the FDI system?


Take a minute to write all the answers on a piece of paper before moving on to the next part, i.e. the key to the above questions.

Key to Revision Exercise

  • Answer 1: Teeth numbers are 18, 28, 38, and 48
  • Answer 2: Teeth names are lower left and lower right canines, central incisors, and lateral incisors.
  • Answer 3: Upper right canine

You should know that things mentioned in the statements of the revision exercise are facts, and the use of modern-day toothbrushes can prevent these problems. One such modern-day toothbrush is Oclean’s Sonic electric toothbrush. Be sure to check it out if you plan on practicing meticulous oral hygiene – to prevent oral diseases.


*Cover image from Freepik, we will delete it if constitutes infringement *

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