FDI Notation
Also written as: FDI — Fédération Dentaire Internationale
The two-digit tooth numbering system developed by the Fédération Dentaire Internationale, in which the first digit identifies the quadrant and the second identifies the tooth within that quadrant.
Full Definition
In FDI (ISO 3950) notation, the mouth is divided into four permanent quadrants (1–4) and four primary/deciduous quadrants (5–8), numbered clockwise from the patient's upper right. The second digit (1–8) identifies the specific tooth from the midline posteriorly. For example, tooth 11 is the maxillary right central incisor; tooth 36 is the mandibular left first molar. FDI notation is the international standard used in most countries outside the United States, where the Universal Numbering System (1–32) predominates. Editors must ensure the correct notation system is consistently applied in clinical documents intended for specific regional or international audiences.
Usage
Usage note: Do not mix FDI and Universal Numbering System notation within the same document. Confirm the target audience's regional convention before editing tooth references.
In Context
- "In the clinical audit, all tooth references were converted to FDI notation to meet the requirements of the international journal." — Clinical research manuscript
- "When editing for a US-based publication, confirm whether the author has used FDI or Universal numbering before making any changes to tooth designations." — Copy-editing checklist