Teeth Numbering Chart: How Are Teeth Numbered in 4 Quadrants?

Have you ever gone to the dentist and heard them say numbers while checking your teeth, but you had no idea what they meant? It seems like everyone else understands, except you.

Don’t worry, that confusion ends today. In this article, we’ll explain what a teeth numbering chart is, why dentists use it, and why it’s so important for your oral health.

What is a teeth numbering chart?

A teeth numbering chart is a table that dentists use to record and identify each tooth’s condition and location. This system ensures clear communication among dental professionals and guides treatment planning effectively. 

Why do dentists number teeth?

Each tooth indeed has a name: incisors, canines, premolars, and molars. But it’s not that simple. For example, we have 8 incisors, 4 canines, 8 premolars, and 12 molars. So, how can you tell exactly which tooth is which?

That’s why dentists use numbers. The teeth numbering chart helps them identify and classify each specific tooth clearly during examination, diagnosis, and treatment, avoiding confusion and ensuring precise care.

Different numbering systems exist, each with its own rules and sequence for permanent and primary teeth.

What are the main teeth numbering systems?

Globally, dentists use several teeth numbering systems. The main ones are:

• Universal numbering system (US): used especially in the United States
• FDI system (World Health Organization): most commonly used in Canada, Saudi Arabia, Latin America, and most European countries, except the UK.
• Palmer tooth numbering system: is primarily used in the UK.

There are other systems, such as Victor Haderup, Woelfel, and MICAP, that are used less commonly. 

Let’s take a closer look at the most widely used systems for permanent teeth (32 in adults) and primary teeth (20 in children).

How does the universal numbering system work?

This system has been accepted by the ADA since 1968.  This one classifies permanent and primary teeth in the following way:

Permanent teeth (Adults)

Uses numbers from 1 to 32 for numbering teeth.

• Upper jaw (maxillary arch):

• • Numbered #1 to #16
  • Starts at #1: upper right third molar (last back tooth on the top right side)
  • Continues along the top teeth towards the left
  • Ends at #16: upper left third molar (last back tooth on the top left side)

• Lower jaw (mandibular arch):

• • Numbered #17 to #32
  • Starts at #17: lower left third molar (last back tooth on the bottom left side)
  • Continues along the bottom teeth towards the right
  • Ends at #32: lower right third molar (last back tooth on the bottom right side)

Primary teeth (milk teeth / children)

Uses letters from A to T for numbering teeth instead of numbers.

• Upper jaw (maxillary arch): A to J (A starts at the upper right second molar, J ends at the upper left second molar)

• Lower jaw (mandibular arch): K to T (K starts at the lower left second molar, T ends at the lower right second molar)

This sequence makes it easy for dentists to identify and document each tooth quickly.

How does the FDI system number teeth?

The FDI teeth numbering chart uses two digits:

• first digit: indicates the quadrant.
• second digit: indicates the tooth’s position within that quadrant.

Unlike the Universal system (continuous 1–32), in the FDI system:

• tooth #1 in each quadrant is always the central incisor (front middle tooth).
• counting starts from the central incisor (#1) and goes backward towards the molars (up to #8 for permanent teeth).

It divides the mouth into four quadrants and counts teeth in each as if they were mirror images.

Permanent teeth (adults)

• First digit (quadrant):

• • 1: upper right
  • 2: upper left
  • 3: lower left
  • 4: lower right

• Second digit (tooth position in the quadrant)

• • 1-2: incisors
  • 3: canine
  • 4-5: premolars
  • 6-7-8: molars

Primary teeth (milk teeth / children)

For primary teeth, quadrants are numbered 5 to 8, following the same logic.

• First digit (quadrant):

• • 5: upper right
  • 6: upper left
  • 7: lower left
  • 8: lower right

• Second digit (tooth position in the quadrant)

• • 1 – 2: incisors
  • 3: canine
  • 4-5: Molars

What is the Palmer tooth numbering system?

The Palmer Tooth Numbering System is widely used, especially by orthodontists and general dentists, for quick and clear communication.

This system uses symbols or brackets to indicate each quadrant, making it easy to identify the exact location of a tooth at a glance.

Quadrant symbols are:

• ┘upper right
• └ upper left
• ┐ lower right
• ┌ lower left

Permanent teeth (adults)

• Each tooth is assigned a number from 1 to 8 in each quadrant.
• Counting starts from the central incisor (#1) and goes backwards towards the third molar (#8).

Primary teeth (milk teeth / children)

• Uses letters A to E instead of numbers.
• Counting starts from the central incisor (A) and goes backwards to the second molar (E) in each quadrant.

Dentists use this system because it’s a quick visual representation, and the quadrant brackets make it easy to write and read tooth positions.

What is a dental chart (odontogram)?