Tooth Numbering Systems Dental Arches Notes
Tooth Numbering Systems
Dental anatomy is the study of the development, eruption, morphology, nomenclature, function, and identification of teeth in the human dentition and their correlation with shape, form, and function with other teeth in the same and opposing arch.
Table of Contents
The knowledge of dental anatomy, occlusion, and physiology is a prerequisite for the dental professional to practice clinical dentistry.
Read And Learn More: Oral Anatomy Notes
Dental Arches
The teeth in the deciduous and the permanent dentition are arranged in arches in each of the two jaws.
Maxillary teeth:
- The upper jaw is called the maxilla and the arch in the upper jaw is Called the maxillary arch. Thus, the teeth in the maxillary arch are called the maxillary teeth.
Mandibular teeth:
- The lower jaw is called the mandible and the arch in the lower jaw is Called the mandibular arch. Thus, the teeth in the lower arch are called The mandibular arch.
The number of teeth present in each arch is the same in the deciduous and the permanent dentition. There are 10 and 16 teeth in each arch of the primary and the permanent dentition.
Each arch can be divided into two quadrants, which are two equal halves on either side of the midline or the midsagittal plane. The quadrants are named clockwise starting from the upper right quadrant. The quadrants in the upper arch are the upper right and the upper left quadrant and the ones in the lower arch are called the lower left and the lower right quadrants.
Thus, there are four quadrants in the oral cavity, i.e.
- Upper right
- Upper left
- Lower left
- Lower right
Classes And Types Of Teeth
Classes of teeth:
Based on the shape, form and function four classes of teeth have been identified in permanent dentition:
- Incisors
- Canines
- Premolars
- Molars
The premolars are absent in the deciduous dentition. The deciduous dentition contains the incisors, canines, and the molars.
Types of teeth:
The classes of teeth are further divided into different types.
Incisors – central incisor and lateral incisor
Premolar – first premolar and second premolar
Molar – first molar, second molar and the third molar
Overview Of The Human Dentition
Dentition is the term used to collectively include the upper and lower teeth.
There are two sets of dentition seen in humans. The occurrence of two sets of teeth is called diphyodont. The dentition seen in humans is
- Primary/deciduous dentition:
- Secondary/permanent/succedaneous dentition
Primary/deciduous dentition:
- There are 20 teeth in the primary dentition
- The teeth begin to develop prenatally at about the 14th week of intrauterine life; and complete development postnatally at approximately 3 years of age.
- The first primary teeth erupt at the age of 6 months; the last primary teeth erupt at 28±4 months.
- The primary teeth remain in the oral cavity unless lost due to dental caries or trauma from about 2 to 6 years of age.
- There are three classes of teeth in each quadrant of the primary dentition; incisors, canines, and molars.
- In each quadrant, from the midline, the teeth present are the incisors (I) (two in number), canine (C) (one in number), and molars (M) (two in number).
Mixed dentition/transition dentition:
- The first permanent/succedaneous/secondary tooth appears in the oral cavity at the age of 6 years.
- Mixed/transition dentition is the time period between the emergence of the first permanent tooth and the time when all the deciduous teeth are lost or shed.
- It lasts from 6 to 12 years of age.
- Both deciduous and permanent teeth are present in the oral cavity.
- It begins with the eruption of the permanent first molar tooth.
- The total number of teeth in the deciduous dentition is 20.
Secondary/permanent/succedaneous dentition:
- The emergence of the permanent teeth begins at the age of 6 years.
- The emergence of all the permanent teeth is completed by about 14–15 years of age (except the third molars which erupt between 18 and 25 years of age).
- The duration of the permanent dentition is beyond the age of 12 years.
- The total number of teeth in the permanent dentition is 32.
Dental Formulae
The dental formula represents the teeth present on one side of the jaw. The teeth present are represented by the first alphabet of the tooth (For Example. ‘I’ for incisor, ‘C’ for canine, ‘M’ for molar).
The dental formula is a ratio comprising a numerator indicating the number of each class of teeth in the upper quadrant and a denominator indicating the number of each class of teeth in the lower quadrant.
Dental formula for the deciduous dentition:
Each quadrant of the primary dentition has two incisors, one canine and two molars and a total of five teeth thus 10 teeth on each side of the jaw.
ICM/ICM = 212/212
Dental formula for the permanent dentition:
Each quadrant of the permanent dentition has two incisors, one canine, two premolars and three molars and a total of 8 teeth, thus 16 teeth in each side of the jaw.
ICMP/ICMP = 2123/2123
Tooth Numbering/Notation System
Tooth numbering systems are used to identify the tooth in relation to the adjacent tooth, position in the arch, and in relation to the midline.
Tooth numbering systems are important as they:
- Help the dentist in recording the data of a patient.
- Standard tooth numbering systems help in sharing the information collected.
- Some of the tooth numbering systems are easy to interpret and save time.
Several tooth numbering systems have been used but there are three tooth numbering systems that are very popularly used and thus described in this chapter.
The three tooth numbering systems used are as follows:
- Universal numbering system
- Zsigmondy/palmer notation system or palmer notation system
- Federation Dentaire Internationale (FDI system) or the World Dental Federation notation
Note: In all the tooth numbering systems, the side of the teeth represented is the patient’s right, i.e. Left and right refer to the patient’s left and right. It represents the right.
Universal Numbering System (Parreidt 1882)
It uses numbers/alphabets depending on the dentition to represent each tooth. Numbers are used for the permanent dentition and alphabets are used for the deciduous dentition.
The numbering starts from the third molar in the upper right and continues clockwise till the third molar in the lower right quadrant.
Permanent dentition:
- Numbers from 1 to 32 are used.
- The numbering starts from the upper right third molar (maxillary right third molar) represented as 1 to the upper left third molar (maxillary left third molar) represented as 16.
- The numbering continues in a clockwise direction from the lower left third molar (mandibular left third molar) represented as 17 to the lower right third molar (mandibular right third molar) represented as 32.
For example, the permanent maxillary left first molar is represented as 16.
Thus, the entire permanent dentition can be represented as follows:
Deciduous dentition:
- It uses alphabets from through I
- The maxillary right second molar is represented as ‘A’. The numbering Continues clockwise to the mandibular right second molar denoted as ‘K’.
For example, the deciduous maxillary left first molar is represented as I.
Thus, the entire deciduous dentition can be represented as follows:
Advantages:
- Simple concept and easy to understand
- Easy to communicate
- Each tooth has a different number/alphabetic notation
- Computer friendly
Drawbacks:
- Tough to memorize
- Time-consuming to picture it graphically while typing it on the
Computer. - Missing teeth/edentulous areas cannot be represented
Zsigmondy Palmer/Palmer Notation System (Adolf Zsigmondy 1861 )
- The Zsigmondy cross or grid was used to represent the quadrants of the oral cavity
- The grid was a modified shape based on the quadrant to be represented
- Upper right quadrant
- Upper left quadrant
- Lower left quadrant
- Lower right quadrant
- The teeth were represented using numbers from 1 to 8 for the permanent Dentition and alphabets from A to E for the deciduous dentition.
Permanent dentition:
- The symbol represents the quadrant.
- Numbers from 1 to 8 are used
- The numbering starts from the midline with the permanent central incisor being 1. The numbering continues progressively to the third molar denoted as 8
For example, the permanent maxillary left first molar is represented as .
The entire permanent dentition can be represented as follows:
Deciduous dentition:
- The symbol represents the quadrant.
- Numbers from a to e are used.
- The numbering starts from the midline with the deciduous central incisor being A. The numbering continues progressively to the second molar denoted as E.
For example, deciduous maxillary left first molar can be represented as .
The entire deciduous dentition can be represented as follows:
Advantages:
- Simple
- Quadrants are used for the primary and permanent dentitions.
- Visualization of the position of the tooth is easier.
- Anomalies/edentulous areas can be easily represented.
Drawbacks:
- Not computer-friendly as it is tough to type the symbol of the tooth
Using the keyboard. - Tough to verbally communicate the tooth number.
Federation Dentaire Internationale (FDI System) Or The World Dental Federation Notation (1970)
Also called the FDI system. It is a two-digit system.
- Simple
- Easy to understand and teach
- Easy verbal communication of the tooth number is possible
- Computer-friendly and thus easy to type
- Widely accepted
- Easy visualization of the position of the tooth
- Prevention of errors while distinguishing between quadrants
- No complicated symbols are used and thus avoid errors.
In the two-digit system:
- The first digit represents the quadrant
- The quadrants are numbered from 1 to 4 for the permanent dentition And 5 to 8 for the deciduous dentition.
- The second digit represents the tooth.
- The teeth are numbered from 1 to 8 for the permanent dentition and 1 To 5 for the deciduous dentition in each quadrant.
Permanent dentition:
- The first digit represents the quadrant. The numbering starts with 1 for the upper right quadrant and continues clockwise to 4 for the lower right quadrant.
- The second digit represents the tooth. The numbering starts with 1 for the central incisor and continues to 8 for the third molar in each quadrant.
For example, the permanent maxillary left first molar is represented as 26 (pronounced as two six).
Note: For each tooth, the two digits are to be pronounced individually. 26 to be pronounced as two-six rather than twenty-six.
The entire permanent dentition can be represented as follows:
Deciduous dentition:
- The first digit represents the quadrant. The numbering starts with 5 for the upper right quadrant and continues clockwise to 8 for the lower right quadrant
- The second digit represents the tooth. The numbering starts with 1 for the central incisor and continues to 5 for the second molar in each quadrant.
For example, the deciduous maxillary left first molar is represented as 64 (pronounced as six four).
The entire deciduous dentition can be represented as follows:
The teeth present in each quadrant of the deciduous and permanent dentition are represented in the table.
Teeth present in each quadrant of the deciduous and permanent dentition:
Tooth Numbering Systems Synopsis
- Dental anatomy is the study of the development, eruption, morphology,
Nomenclature, function, and identification of teeth in the human dentition and their correlation with shape, form, and function with other teeth in the same and opposing arch. - Maxillary teeth: The teeth in the maxillary arch are called the maxillary teeth.
- Mandibular teeth: The teeth in the lower arch are called the mandibular arch.
- Dentition is the term used to collectively include the upper and lower teeth.
- There are two sets of dentition seen in humans. The occurrence of two sets of teeth is called diphyodont. The dentitions seen in humans are
- Primary/deciduous dentition
- Secondary/permanent/succedaneous dentition
- The dental formula represents the teeth present on one side of the jaw. The teeth present are represented by the first alphabet of the tooth (e.g. ‘I’ for incisor, ‘C’ for canine, ‘M’ for molar.
- Tooth numbering systems are used to identify the tooth in relation to the adjacent tooth, position in the arch and in relation to the midline.
- The three tooth numbering systems used are:
- Universal numbering system
- Zsigmondy/palmer notation system or palmer notation system
- Federation Dentaire Internationale (FDI system) or the World dental
- Federation notation
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