Teeth Names & Numbers

The Universal Numbering System is a simplified method of identifying teeth that is approved and adopted by the American Dental Association.

In the universal tooth numbering system, tooth number 1 is the patient's upper right third molar, on the right side of the mouth in the upper (maxillary) jaw. Numbering of teeth continues along the upper teeth toward the front and across to the last molar tooth back on the top left side (number 16). The tooth numbering continues by assigning teeth numbers descending to the lower left third molar (number 17) and follows the lower (mandibular) jaw up to the tooth farthest back on the bottom right side of the mouth (number 32). All teeth that should be there are numbered, including those teeth that have been removed for any reason or have not erupted yet (e.g. wisdom teeth).

In the original system, children's 20 primary teeth are numbered in the same order (from 1 to 20), except that a small letter "d" follows each number to indicate deciduous (primary) teeth.

However, most dentists today use a modified version of the Universal Numbering System for children, with letters instead of teeth numbers. The primary teeth are designated by upper case letters A through T, with A being the patient's upper right second primary molar and T being the lower right second primary molar.

Universal tooth numbering system Teeth numbering chart for adult teeth upper left upper right lower left lower right Orientation of the Universal tooth numbering chart is traditionally "patient's view", i.e. "left" and "right" on the chart correspond to the patient's left and right, respectively. - tooth number diagram 1a - Universal tooth numbering system Teeth numbering chart for deciduous (primary) teeth upper left upper right lower left lower right - tooth number diagram 1b -

The second system, developed by the Fédération Dentaire Internationale (FDI), World Dental Federation notation is also known as ISO-3950 notation.

The human teeth are symmetrically arranged in the mouth. Each quadrant of the mouth has 8 different teeth that are mirrored horizontally and vertically to the other quadrants. In the FDI notation each one of these 8 teeth is assigned a number from 1 to 8, starting from the center front tooth (central incisor) and moving backwards up to the third molar (number 8). Each quadrant is also assigned a number, from 1 to 4 for the adult (permanent) teeth or 5 to 8 for the baby (primary or deciduous) teeth.

The combination of these two numbers (Quadrant code number & Tooth code number) specifies how are teeth numbered. This tooth numbering system is called, the Two-Digit World Dental Federation Notation or FDI notation system.

Adults FDI tooth numbering system Teeth numbering chart for adult teeth upper right upper left lower right lower left Orientation of the FDI two-digit tooth numbering chart is traditionally "dentist's view", i.e. patient's right corresponds to teeth number chart's left side. The designations "left" and "right" on the chart, however, correspond to the patient's left and right. - tooth number diagram 2a -   Children FDI tooth numbering system Teeth chart for primary teeth upper right upper left lower right lower left - tooth number diagram 2b -

Teeth names are created by a combination of 4 different characteristics:

1. The jaw where they are located: upper and lower (alternatively the terms maxillary and mandibular can be used)
2. The side of the face: left and right
3. The type of tooth: incisor, canine, premolar, and molar
4. A secondary name for the teeth types that appear more than once in each quadrant of the mouth e.g. central and lateral for incisors, first and second for premolars, first, second, and third for molars.

Based on these characteristics, the teeth names for the permanent dentition are the following (starting from the upper right back tooth and moving anti-clockwise):

Next to its tooth you can see the tooth number based on:
     a) the Universal Numbering System (UNS) used in the United States and b) the FDI notation (FDI)

Permanent Teeth Names & Numbers

Left and Right on the teeth chart correspond to the patient's left and right respectively (patient's view).

Primary (Baby or Deciduous) Teeth Names & Numbers

For primary teeth, most dentists in United States use a modified version of the Universal Numbering System, with each primary tooth assigned a letter (from A to T) instead of a number.

Left and Right on the teeth chart correspond to the patient's left and right respectively (patient's view).

Other common teeth names:

• Cuspids: Another name for canines
• Bicuspids: Another name for premolars
• 6 year molar: Another name for first permanent molar
• 12 year molar: Another name for second permanent molar
• Wisdom Teeth: A popular name for the third molars
• Anterior Teeth: The teeth in the front of the mouth including central incisors, lateral incisors, and canines.
• Posterior Teeth: The teeth in the back of the mouth including premolars and molars.
• Mandibular Teeth: The teeth on the lower jaw
• Maxillary Teeth: The teeth on the upper jaw