Dental Notation Guide

In children, the Palmer Notation System uses uppercase letters instead of numbers.  Following the same order as for adult’s teeth, children’s 20 primary teeth are lettered “A” through “E” in each quadrant.  The same symbol is used to identify the quadrants. In the original system, children’s 20 primary teeth are numbered in the same order, except that a small letter “d” follows each number to indicate deciduous (primary) teeth.  So, a child’s first tooth on the upper right would be 1d and the last tooth on the lower right would be 20d.

However, most dentists and insurance companies now use a modified version of the Universal Numbering System for children. This version uses the letters A through T instead of the number 1 through 20.  So, a child’s first tooth on the upper right would be A and the last tooth on the lower right would be T.  -Source