About Teeth Numbers

Who runs it

Teeth Numbers is run by Becky Schmidt. It's an independent reference site, not a dental practice, and no dental professional has reviewed the pages. That's why every fact links to the published source it comes from.

The site exists because tooth numbers are confusing: the same number means different teeth in different systems, and charts online rarely say which system they use. Here, every tooth is shown in all three.

Where the data comes from

  • Tooth numbers (Universal and FDI): the American Dental Association'sUniversal Tooth Designation System – Value Set (July 2024). It lists every adult and baby tooth with its Universal number or letter and its FDI (ISO 3950) number.
  • Palmer notation: Edward F. Harris, Tooth-Coding Systems in the Clinical Dental Setting(Dental Anthropology 18(2):43–49, 2005). It explains the quadrant mark and the 1–8 and A–E numbering.
  • When teeth come in and fall out: the ADA's eruption charts for adult and baby teeth.
  • Roots and canals: peer-reviewed scan studies and reviews, listed on each tooth's page. Teeth vary between people and populations. Where studies disagree, the page gives the range and says so.

How it's checked

Pages are written with help from AI tools, from the sourced data. A script then recalculates every tooth's Universal, FDI and Palmer numbers from scratch, compares each one with the ADA's own table, and checks every eruption age against the ADA charts. A page isn't published if any check fails. The data was last verified on October 10, 2026.

Each root and canal figure is matched word for word to the study it comes from. For a few large studies in theJournal of Endodontics only the published summary (abstract) was available, so those figures come from the abstract.

Sources make mistakes too. One example: the ADA document's introduction calls tooth K the lower right second molar, but its own table, and the A–T order, make it the lower left second molar. This site follows the table.

Found a mistake?

Email corrections@teethnumbers.org with the page and what looks wrong, and a link to a source if you have one. Every report gets checked against the original sources, and confirmed mistakes are fixed on the site.

What this site is not

It explains tooth names, numbers and typical anatomy. It isn't medical or dental advice, and it can't tell you what's going on with a particular tooth. Your dentist can.

All studies used