Dental notation

# Overview
Dentists, in writing or speech, use several different Dental notation systems for associating information to a specific tooth.  The three most commons systems are the FDI World Dental Federation notation, Universal numbering system (dental), and Palmer notation method.  The FDI system is used worldwide, and the universal is used widely in the USA.

# History
A committee of the American Dental Association (ADA) recommended the use of the Palmer notation method in 1947.  Since this method required the use of symbols, its use was difficult on keyboards.  As a result, the association officially supported the universal system in 1968.  The World Health Organization and the Federation Dentaire Internationale officially uses the two-digit numbering system of the FDI system.

# Palmer notation method
The Palmer notation is a system used by dentists to associate information to a specific tooth. Although supposedly superseded by the FDI World Dental Federation notation, it overwhelming continues to be the preferred method used by dental students and practitioners in the United Kingdom.  It was originally termed the "Zsigmondy system" after the Hungarian dentist Adolf Zsigmondy who developed the idea in 1861, using a Zsigmondy cross to record quadrants of tooth positions.. Adult teeth were numbered 1 to 8, and the child primary dentition (also called deciduous, milk or baby teeth) were depicted with a quadrant grid using Roman numerals I, II, III, IV, V to number the teeth from the midline distally. Palmer changed this to A, B, C, D, E.
The Palmer notation consists of a symbol ( ) designating in which quadrant the tooth is found and a number indicating the position from the midline. Adult teeth are numbered 1 to 8, with deciduous (baby) teeth indicated by a letter A to E. Hence the left and right maxillary central incisor would have the same number, "1", but the right one would have the symbol, "", underneath it, while the left one would have, "".

# Universal numbering system
The Universal numbering system is a dental notation system for associating information to a specific tooth, and is commonly used in the United States.  The uppercase letters A through T are used for primary teeth and the numbers 1 - 32 are used for permanent teeth.  The tooth designated "1" is the right maxillary third molar and the count continues along the upper teeth to the left side.  Then the count begins at the left mandibular third molar, designated number 17, and continues along the bottom teeth to the right side.  Each tooth has a unique number or letter, allowing for easier use on keyboards.

# FDI World Dental Federation notation
The FDI World Dental Federation notation is widely used by dentists internationally to associate information to a specific tooth.  Developed by the Federation Dentaire Internationale (FDI), it is also known as ISO-3950 notation.  The FDI system uses a two-digit numbering system in which the first number represents a tooth's quadrant and the second number represents the number of the tooth from the midline of the face.  For permanent teeth, the upper right teeth begin with the number, "1".  The upper left teeth begin with the number, "2".  The lower left teeth begin with the number, "3".  The lower right teeth begin with the number, "4".  For primary teeth, the sequence of numbers goes 5, 6, 7, and 8 for the teeth in the upper left, upper right, lower right, and lower left respectively.