TeethThe tooth anatomy is an interesting but challenging topic that demands the respect of any health science student or professional. The human teeth are quite special because they grow twice during an adult’s lifespan, are essential structures for the mechanical digestion of food, and support certain facial features.
Adult dentition consists of thirty-two teeth that share some common anatomical features and are classified into four groups:
In this page, we are going to study each one of the above types, learn how they are numbered, and understand the various anatomical parts of teeth.
Prefer to learn by doing? Look no further than our dental anatmy quizzes and tooth diagrams.
|Types of teeth||Deciduous dentition (20 teeth), permanent dentition (32 teeth)|
|Teeth Numbering/notation systems||
ISO/FDI system (International standard), Universal System (US), Palmar system (UK)
|Main parts of a tooth||Crown, pulp chamber, neck, dental root, root canal|
Arteries: anterior superior alveolar arteries, posterior superior alveolar arteries, inferior alveolar arteries
Nerves: Superior alveolar nerves (CN V2), inferior alveolar nerves (CN V3)
- Teeth names and numbering
- Types of teeth
- Teeth anatomy
- Arteries and veins
- Related diagrams and images
Teeth names and numbering
There are thirty-two teeth in total in the oral cavity of an adult with a healthy dentition. One half, or sixteen, are embedded in the maxilla, while the lower half are situated within the mandible. The name of teeth on each arcade is self-explanatory - the top sixteen are named ‘maxillary teeth’, while the bottom half are named ‘mandibular teeth’. Each arcade is similar but not identical to its counterpart.
The teeth on each row, or arcade, are divided into four groups; named as follows from the dental midline outwards:
- Incisors (4) - central incisors, lateral incisors
- Canines (2)
- Premolars (4) - first premolars, followed by the second premolars
- Molars (6) - first molars, then second molars, and finally the third (wisdom tooth) molars
Tackle the following quiz to learn the names of teeth.
For simplification purposes, dental professionals use a variety of numbering systems to identify the various teeth.
FDI notation system
The Féderation Dentaire Internationale (FDI notation system) also known as the ISO system is the international standard for the numbering and naming of teeth, as defined by the World Health Organisation. Each tooth is denoted by two numbers.
The first number refers to the quadrant in which the tooth is located:
- Right upper/maxillary quadrant = 1
- Left upper/maxillary quadrant = 2
- Left lower/mandibular quadrant = 3
- Right lower/mandibular quadrant = 4
The second number refers to the position of the tooth within the quadrant:
- Central incisor = 1
- Lateral incisor = 2
- Canine = 3
- 1st premolar = 4
- 2nd premolar = 5
- 1st molar = 6
- 2nd molar = 7
- 3rd molar = 8
Therefore, the 2nd premolar of the upper left quadrant uses the notation '25'.
Universal numbering system
The American Dental Association Universal Numbering System is mainly used in the United States. The teeth are numbered 1 to 32; superior right to left, then inferior left to right.
Palmer notation system
Palmer notation (sometimes referred to as 'Zsigmondy notation') is the primary system used for the numbering of teeth in the United Kingdom.
Similar to the FDI system, it divides the dentition into four quadrants with each tooth numbered between 1-8 as outlined above. The number is assigned a quadrant by means of the following symbols - ┘└ ┐┌
- Right upper/maxillary quadrant = ┘
- Left upper/maxillary quadrant = └
- Left lower/mandibular quadrant = ┐
- Right lower/mandibular quadrant = ┌
Therefore, the 2nd molar of the lower left quadrant would have the notation '. '5┐'.
Watch the following teeth video to find out more about the four groups and their numbering.
Types of teeth
In addition to the specific naming and numbering, dental anatomy is also unique in the possible types of teeth and their respective numbers. Children have twenty teeth, called deciduous or milk teeth, between six months and six years of age. This set is subsequently replaced by the permanent dentition of thirty-two teeth in adolescence and adulthood. Read the following article to find out more details about the two types of human teeth.
The four groups of teeth are not identical, but they all share a typical and general tooth anatomy, as follows:
- Pulp chamber
- Neck of tooth
- Dental root
- Root canal
Arteries and veins
The blood supply of the teeth originates from the maxillary artery, which is the largest terminal branch of the external carotid artery. It is responsible for supplying the deep structures of the face.
The specific arteries carrying blood to the teeth travel through the root canal and have the following names:
- Anterior superior alveolar arteries
- Posterior superior alveolar arteries
- Inferior alveolar arteries
The veins of the teeth follow the arteries, having similar names. They drain into the pterygoid plexus or the facial vein.
The nerves supplying the teeth also accompany the arteries through the root canals and originate from the maxillary and mandibular branches of the trigeminal, or fifth, cranial nerve. Near the teeth, these major nerves give rise to the following branches:
- Superior alveolar nerves
- Inferior alveolar nerves
Reinforce your knowledge about teeth by taking this specially designed quiz. This teeth anatomy quiz is customized in way that it covers the structure and neurovasulature of the teeth.