About
ToothNotation exists to answer one question quickly: what does this charting entry refer to? Enter #19 MOD and you get the tooth and its surfaces, rather than a chart image to count across.
Who it is for
Dental assistants, hygienists, students, and administrative staff who read or write operative chart entries, plus clinicians checking a cross-reference between numbering systems. It assumes you want the notation resolved, not dental anatomy taught from first principles.
What it covers, and what it does not
It covers tooth numbering in the ADA Universal, FDI (ISO 3950) and Palmer systems for all 32 permanent and 20 primary teeth, the seven standard tooth surface codes, and the combinations built from them.
It does not cover diagnosis, treatment planning, materials, or billing and procedure codes. Notation says which tooth and which surfaces. It never says what was found or what was done, and this site will not imply otherwise.
Where the definitions come from
Surface code definitions follow the tooth surface code list published by the US Centers for Medicare & Medicaid Services. The numbering systems follow the ADA Universal sequence and the FDI/ISO 3950 quadrant scheme. The conversion between systems is derived from those published rules and is covered by an automated test over all 52 teeth, which runs on every build — so a mistake in one tooth cannot ship quietly.
Where something is not standardised, this site says so rather than inventing an authority. Restoration and condition abbreviations vary by practice, school, region and software; the abbreviations page presents them as convention and tells you to verify them locally. That distinction is deliberate and is the main editorial rule here.
Independence and ownership
This is a free reference with no advertising, no sponsored placement, and no product recommendations. Nothing on it is ranked, ordered or worded to favour any manufacturer or supplier. It is published by a company working in the dental sector; the responsible legal entity is named in the Privacy Policy and Terms.
Corrections
If a tooth resolves incorrectly, a definition is wrong, or the decoder mishandles an expression you use in practice, please report it — those are the most useful messages this site receives, and reference data errors are corrected as a priority. Use the contact page.
Privacy of what you type
The decoder runs entirely in your browser. Expressions you enter are not sent to any server, not stored, and not logged. There is no login and nothing to opt out of.