TOOTH NUMBERING SYSTEM
Tooth numbering systems were originally developed as a shortcut to minimize the effort of hand-written record-keeping in dentistry. To identify a specific tooth, arch, quadrant, and the tooth’s name.
Currently, only three most popular systems are favored worldwide. These popular systems are
as follows:
• The Zsigmondy/Palmer (the eight-tooth quadrant) system
• The universal system
• The FDI/two digit system.
Zsigmondy/Palmer System
- First published in 1861 by Viennese dentist Adolf Zsigmondy.
- Tooth numbering for permanent teeth is done starting with 1 for the central incisors and ending with 8 for the third molars.
Universal System
- ADA Recommended the Universal System
- This tooth numbering system was proposed by German dentist Julius Parreidt in 1882.
- In this numbering system, the upper right third molar is identified as ‘1’. The sequence then moves in a clockwise direction around the arch, ending with the lower right third molar, which is numbered as ’32’.
- Originally, primary teeth were not part of this system; Later they were added and are denoted by alphabetical letters from A to T, proceeding clockwise like permanent teeth.
- MODIFICATION : In 1967, Goodman proposed the use of numerals from ‘41’ through ‘60’, instead of A-to-T, as a modification to Universal system for Primary Teeth.
FDI System/Two Digit System
- It is also known as FDI notation system or two digit system or ISO 3950 notation or International numbering system.
- FDI is denoted as Federation Dentaire Internationale.
- The tooth numbering system is formed by a special committee on uniform dental recording. The committee passed a resolution at the FDI General Assembly meeting in 1970 at Bucharest, Romania.
- As per FDI, following criteria should meet FDI tooth
notation system, i.e.
1. It should be simple to teach and understand.
2. It should be easy to pronounce.
3. It should be easily printable.
4. It should be easily translated into computer output.
5. It should be easily adapted to standard charts which are used in general practice. - In FDI system two digits are used, the first digit denotes the quadrant and the second digit denotes the tooth. That’s why FDI named this as two digit system.
- FDI Notation for Permanent Dentition
♦ In this mouth is divided in four quadrants.
♦ First digit represents the quadrant. Quadrants are 1 to 4 for permanent dentition.
♦ Second digit represents the tooth in the particular quadrant. Each of the quadrant in permanent dentition has 8 teeth which are designated with numbers 1 to 8.
♦ Two digits should be pronounced separately.FDI Notation for Deciduous Dentition
♦ Four quadrants are designated as 5 to 8 in clockwise direction.
♦ First digit represents quadrant from 5 to 8
♦ Second digit represents tooth in particular quadrant from 1 to 5