International (F.D.I) Shorthand Numbering System
International (F.D.I) Shorthand Numbering System for the Secondary Dentition
The International (or F.D.I. or Fédération Dentaire Internationale) shorthand system is used throughout the world as the shorthand method of choice except in the United States. This system has two numbers for each tooth. The first number represents the quadrant. Quadrants are numbered in a clockwise manner from the maxillary right to the mandibular right. The quadrants for the secondary dentition in this system are 1 (maxillary right), 2 (maxillary left), 3 (mandibular left) and 4 (mandibular right).
FDI System Naming of Quadrants for the Secondary Dentition |
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1 = Maxillary right |
2 = Maxillary left |
4 = Mandibular right |
3 = Mandibular left |
The second number in this system represents the secondary tooth from 1 (central incisor) to 8 (third molar).
FDI System Naming of Teeth for the Secondary Dentition |
1 = central incisor 2 = lateral incisor 3 = canine 4 = first premolar 5 = second premolar 6 = first molar 7 = second molar 8 = third molar |
The International system may or may not have a "period" between the quadrant and the tooth. The National Dental Examining Board of Canada includes a "period" between the quadrant number and the tooth number as this allows a clear differentiation between the Universal and International systems. The "official" F.D.I. numbering system, however, does not use a period between the two numbers. Unfortunately, this can sometimes lead to confusion as tooth 24 in the International system is the secondary maxillary left first premolar while in the Universal system tooth 24 is the secondary mandibular left central incisor.
The pronunciation also differs between the Universal and the International systems. The secondary maxillary left first molar in the Universal system is tooth 14 and is pronounced as "fourteen". The shorthand designation for the same tooth in the International system is tooth 2.6 or 26. However, it is pronounced as tooth " two six" in this system.
Click on the movie icon above to view the FDI shorthand system.
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Rollover image to identify the longhand and FDI shorthand for each tooth. | |
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Rollover image to identify the longhand and FDI shorthand for each tooth. | |
International (F.D.I.) Shorthand Numbering System for the Primary Dentition
The first of the two numbers used in the International shorthand numbering system for the primary dentition is the quadrant number. The quadrants are numbered 5-8 when using the International system for the primary dentition.
FDI System Naming of Quadrants for the Primary Dentition |
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5 = Maxillary right |
6 = Maxillary left |
8 = Mandibular right |
7 = Mandibular left |
The second number in the International system is the specific tooth. In the primary dentition each quadrant contains a total of 5 teeth. Therefore there are a total of 20 teeth in the primary dentition.
FDI System Naming of Teeth for the Primary Dentition |
1 = central incisor 2 = lateral incisor 3 = canine 4 = first molar 5 = second molar |
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Rollover image to identify the longhand and FDI shorthand for each tooth. | |
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Rollover image to identify the longhand and FDI shorthand for each tooth. | |