Teeth Numbering System for Adults and Children

Dentists around the world make use of a teeth numbering system to specifically identify teeth in human adults and children. They have allotted numbers to the whole set of teeth and this makes it easy for them to prepare reports and mention a particular tooth. There are around 20 different teeth numbering systems but the dentists make use of some of the standard numbering system to maintain uniformity and to avoid confusions.

The Human Adult Teeth

The human set of teeth contains four groups of teeth:

  • The incisors, which are used for cutting;
  • The canines, which are used for tearing purpose;
  • The premolars, which help in chewing food; and finally,
  • The molars, which grind food

The adult teeth chart applies to a person who has all his teeth developed and this includes the third molar as well. The third molar is also called the wisdom tooth.

Standard Numbering System for Teeth

There are mainly two systems that are commonly followed by dental care specialists round the world: the Universal System and the FDI System. The basic difference between the two is the way the teeth are numbered. While the Universal System follows a serial order for numbering, the FDI one uses a quadrant on a dental chart to mark the teeth.

1.)  Universal System for Teeth Numbering

For Adults:

The Universal system for dental teeth numbering numbers all the teeth in a serial order. The numbers are allotted in serial order to all the teeth of the upper jaw before moving to the lower jaw. The numbering starts with the Number 1, which is allotted to the upper right third molar or more popularly known as the wisdom tooth. Numbering for the upper jaw ends on the upper left wisdom tooth at Number 16. Now, for the lower jaw, the numbering starts from the left wisdom tooth and it is allotted the Number 17 and the series ends on the lower right wisdom tooth, which is allotted the Number 32.

For Children and Babies:

Children and baby teeth numbering is also similar but with a slight difference. Small children and babies don’t have molar teeth. The numbers remain the same as in the adult teeth numbering system but the numbers specified for all the molars are omitted and the numbers are marked along with a letter ‘d’, which indicates that the teeth are ‘deciduous’ or ‘primary teeth’.

2.)    The FDI Two Digit Numbering System for Adults

For Adults:

Also called the ISO-3950 notation numbering system, the FDI system is used by most dentists round the world. This dentist teeth numbering system is based on a quadrant. The numbers in each quadrant go up from 1 until 8.

The upper right quadrant is marked as 1 and the numbering starts from the central incisor, which is marked as 11 and continues to the third molar, which is marked as 18. Similarly, the same is done for the upper left quadrant as well. The central incisor is marked as 21 and the upper left third molar is marked as 28. The lower right quadrant is marked as 4 and the lower left quadrant is marked as 3 with 48 and 38 being the two lower wisdom teeth, respectively.

For Children and Babies:

The same numbering system is used here, too, but with a slight difference. The upper right quadrant is marked as 5, upper left as 6, the lower left as 7 and the lower right as 8. Since the children don’t have molars, the numbers move up from 1 to 5 in each quadrant.