There are three different tooth numbering systems:
Palmer's Method of Tooth Notation
(also known as: Military Tooth Numbering System)
A system for designating teeth by number and quadrant. The oral cavity is divided into quadrants and each tooth is designated by an Arabic numeral 1 to 8, starting with the central incisor in each quadrant and continuing posteriorly to the third molar. The quadrant is indicated by a right angle symbol oriented right or left and up or down. The system was popular in the 1950s but is no longer in general use except in orthodontic practices. (Mosby's Dental Dictionary, 2nd edition. © 2008 Elsevier, Inc.)
Universal Numbering System
A tooth-numbering system in which the secondary teeth are numbered from 1 (the maxillary right third molar) to 32 (the mandibular right third molar). The primary teeth are similarly numbered from 1 to 20, with the numbers preceded by the letter D (for deciduous). The universal tooth coding system is similar to the ADA numbering system, except that the latter uses the letters A to T to identify the deciduous teeth. (Mosby's Medical Dictionary, 8th edition. © 2009, Elsevier.)
FDI World Dental Federation Notation
Widely used by dentists internationally to associate information to a specific tooth.[1]
Developed by the FDI World Dental Federation, World Dental Federation notation is also known as ISO 3950[2] notation.
Orientation of the chart is traditionally "dentist's view", i.e. patient's right corresponds to notation chart left. The designations "left" and "right" on the chart, however, nonetheless correspond to the patient's left and right, respectively.
Denticon utilizes the Universal Numbering System.