primary dentition

n.
  1. The first set of teeth, 20 in all, that usually erupt between the sixth and 28th months.
  2. The eruption of the first set of teeth.deciduous dentition
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.