This document discusses four common tooth numbering systems: 1) The Universal System numbers teeth from 1-32 for permanents and A-T for primaries, specifying dentition, arch, and tooth name. 2) The Palmer System uses quadrant designations (A, B, C, D) with tooth name for primaries and numbers for permanents. 3) The FDI System assigns two-digit numbers to each tooth, specifying dentition, arch, side, and tooth name. 4) The Haderup System assigns + or - numbers/letters to each tooth based on its location in the arch.