FDI Notation
Also written as: FDI — Fédération Dentaire Internationale
The internationally standardised two-digit tooth numbering system developed by the Fédération Dentaire Internationale, used in most countries outside the USA.
Full Definition
FDI notation assigns each tooth a two-digit code: the first digit identifies the quadrant (1–4 for permanent teeth, 5–8 for primary teeth) and the second identifies the tooth's position within that quadrant (1–8 from central incisor to third molar). For example, tooth '36' denotes the lower left first molar. Editors must be alert to the distinction between FDI, Palmer (UK-traditional), and Universal (US) notation systems, as errors in transcription can mean the wrong tooth is identified in clinical and legal records. Journals, referral letters, and reports may use different systems depending on national context.
Usage
Usage note: In FDI notation, the two digits are written without a space or hyphen (e.g., '36' not '3-6' or '3 6'). Editors should standardise notation throughout a document and note any system change in a query to the author.
In Context
- "The referral used Palmer notation while the specialist's reply employed FDI notation, creating a tooth-identification discrepancy requiring editorial correction." — Specialist referral correspondence
- "Per the journal's style guide, all tooth references should follow FDI notation with no space between the two digits." — Academic dental journal article