The Universal Numbering System, sometimes called the "American System", is a dental notation system commonly used in the United States.[1][2]
Most of the rest of the world uses the FDI World Dental Federation notation, accepted as an international standard by the International Standards Organization as ISO 3950.[3] However, dentists in the United Kingdom commonly still use the older Palmer notation despite the difficulty in representing its graphical components in computerized (non-handwritten) records.