Overview
EN ISO 10394:2024 (identical to ISO 10394:2023) specifies a standardized, two-character designation system for supernumerary teeth in humans. The standard defines an alphanumeric code that locates extra (supernumerary) teeth relative to the normal dentition using a compact, computer-friendly format designed for clinical records, dental software and data exchange. It was adopted by CEN as EN ISO 10394:2024 to ensure consistent use across European national standards bodies.
Key topics and requirements
- Two-character format: Every supernumerary tooth is designated by two characters (one letter + one digit, or two letters for midline cases) to align with existing two-character systems.
- Quadrant identifier (first character):
- A = quadrant 10 (upper right)
- B = quadrant 20 (upper left)
- C = quadrant 30 (lower left)
- D = quadrant 40 (lower right)
- Tooth-location digit (second character): Digits 1–8 indicate position within a quadrant (e.g., 1 = central incisor area, 2 = lateral incisor area, …, 8 = third molar area). Table 1 in the standard maps these codes to normal tooth positions.
- Midline designations: Two-letter codes identify midline supernumeraries:
- AB = midline of the maxilla (upper jaw)
- DC = midline of the mandible (lower jaw)
- Location rules:
- Designation relates the supernumerary tooth to the normal tooth at that site or immediately mesial to it.
- If a supernumerary tooth overlaps more than one normal location, use the mesial-most extent for designation.
- The system does not specify bucco‑lingual position and does not classify teeth as deciduous or permanent.
- Multiple supernumerary teeth in the same location use the same code.
- Compatibility constraint: The system intentionally retains the two-character format and avoids redefining codes already used by ISO 3950 to preserve interoperability.
Applications and users
This dentistry standard supports consistent identification, reporting and data exchange for supernumerary teeth across clinical and technical environments:
- Dentists, orthodontists and oral surgeons for charting and treatment planning
- Dental radiologists for standardized radiographic reporting
- Electronic health record (EHR) and dental practice management software developers for coding and messaging
- Dental researchers and epidemiologists collecting prevalence and outcome data
- Standards bodies and terminologists aligning dental vocabularies
Practical benefits include improved interoperability, clearer communication in referrals/records, and easier integration with existing tooth designation systems.
Related standards
- ISO 3950 - Designation system for teeth and areas of the oral cavity (related, but not extended for supernumeraries)
- ISO 1942 - Dentistry - Vocabulary (normative reference used in EN ISO 10394:2024)
Keywords: EN ISO 10394:2024, ISO 10394:2023, supernumerary teeth, designation system, dentistry standard, dental coding, tooth designation, dental interoperability.