Names of teeth in human mouth


Better the understanding of the oral cavity and the structures present within it, quicker do we realize our responsibility towards their maintenance.

The 32 teeth lying embedded within the bone in the oral cavity not only help us eat, speak and smile but also contribute to our facial profile.

These structures are inherited and we should know how these structures are named, classified when they develop and what they are made up of so that they can be taken care of in the best possible way.

Teeth are of four types 

1) Incisors


Incisors are the front teeth. They are chisel-shaped. Incisors are 8 in number. 4 in the upper jaw and 4 in the lower jaw. These teeth help in the biting and incision of food.

2) Canines


Canines are pointed in shape and help tear food. Canine is the longest tooth. These are four in number, 2 in the upper jaw and 2 in the lower jaw. They lie beside the incisor teeth and form the cornerstones of the mouth. They are also known as the cuspids because they have a pointed tip.

3) Premolars

Premolars help in tearing and crushing food. They are 8 in number. 4 in the upper jaw and 4 in the lower jaw (2 in each quadrant). They are present behind the canine. Premolars are also known as the bicuspids since they have two cusps.

4) Molars

Molars are the largest teeth with the greatest biting ability. Molars are 8 to 12 in number. They are present behind the premolars.

Baby Teeth

When babies are born, their teeth are not visible in the mouth. During this time, these teeth lie within the jawbone. At the age of 6 months, the baby teeth start appearing in the child’s mouth. It takes 33 months for all baby teeth to emerge through the gums.

Baby teeth are also known as milk teeth or primary teeth. Baby teeth are less in number. There are a total of 20 baby teeth in children (Premolars are not present in the baby teeth)

The function of baby teeth is to enable the child to speak and to eat. These baby teeth get replaced by permanent teeth from the age of 6 years.


The difference between baby teeth and permanent teeth is in size and shape. Baby teeth are smaller in size. As a child’s age advances, the jaw increases in size. During childhood, the jaws are small. Hence the size of baby teeth is also small so that they can fit in the child’s oral cavity.

The health of baby teeth is vital. Baby teeth act as a guide for the growth of underlying permanent teeth. Baby teeth may get decayed and exfoliate at an early age. A premature exfoliation indicates an early eruption of the permanent tooth. Incorrect time of eruption can lead to crowding in the teeth. Also, the infection of baby teeth can get transmitted to the underlying permanent teeth.

When do babies start teething ?

Teething starts at the age of 6 months and completes at the age of 33 months. The underlying chart gives you an overall idea about when each tooth erupts.

Upper Teeth

Central incisor –> 8 to 12 months

Lateral incisor –> 9 to 13 months

Canine –> 16 to 22 months

First Molar –>13 to 19 months

Second Molar –> 25 to 33 months

Lower Teeth

Central incisor –> 6 to 10 months

Lateral incisor –> 10 to 16 months

Canine –> 17 to 23 months

First Molar –> 14 to 18 months

Second Molar –> 23 to 31 months

The eruption of baby teeth is completed when the baby turns 3 years old.

When do permanent teeth erupt?

Humans have two sets of teeth in their entire lifetime. The 20 baby teeth are replaced with 32 permanent teeth. This replacement starts at the age of 6 years. The underlying chart gives you an idea about when the permanent tooth erupts

Upper Teeth

Central incisor –> 7 to 8 years

Lateral incisor –> 8 to 9 years

Canine –> 11 to 12 years

First premolar –> 10 to 11 years

Second premolar –> 10 to 12 years

First molar –> 6 to 7 years

Second molar –> 12 to 13 years

Third molar –> 17 to 21 years

Lower Teeth

Central incisor –> 6 to 7 years

Lateral incisor –> 7 to 8 years 

Canine –> 9 to 10 years

First premolar –> 10 to 12 years

Second Premolar –> 11 to 12 years

First molar –> 6 to 7 years

Second molar –> 11 to 13 years

Third Molar –> 17 to 21 years

Different parts of a tooth

A tooth is externally made up of two parts:

1) Crown

The upper portion of the tooth is the crown. It is the only part of the tooth which is visible in the oral cavity. It is made up of enamel, dentin and pulp. Crowns are of different shapes and sizes. The shape and size are according to the function the tooth serves.

2) Root

The lower portion of the tooth is the root. It is that part of the tooth which is present inside the alveolar bone. It is made up of enamel, dentin, pulp and cementum. The number, shape and size of the dental root are different for each tooth.

  • An incisor has one root
  • A canine has one root
  • A premolar can have 1 or 2 roots
  • A molar can have a maximum of three roots

A tooth is internally made up of three parts:

1) Enamel

It is the outermost layer of a tooth. The color ranges from white to light yellow. The enamel is mainly made up of calcium. It is the hardest part of the tooth. It protects the inner layers from trauma or infection. Inability to maintain good oral hygiene can cause a bacterial attack on the enamel. This can lead to the spreading of infection to the underlying layers of a tooth.

2) Dentin

This layer lies within the enamel. It is dark yellow in color. When dentin gets exposed, there is sensitivity experienced. This sensitivity is due to the exposure of nerves traversing the dentinal layer of the tooth. Its function is to protect the underlying pulpal tissue.

3) Pulp

This is the innermost layer of the tooth. It is made up of nerves, vessels and connective tissue. Any infection involving the pulpal tissue requires root canal treatment.

4) Cementum

This layer is present surrounding the tooth root. It helps attach the tooth to the bone and also avoids the tooth from getting resorbed.

Teeth Numbers

The oral cavity is divided into four quadrants (upper right, upper left, lower right and lower left).

Each tooth is given a specific number which makes it easier for the dentist to refer to each tooth.

FDI world dental federation numbering system is one of the preferred methods for numbering teeth which is as follows:

Permanent teeth: There are eight permanent teeth present in each quadrant

First Quadrant

11 – Central incisor

12 – Lateral incisor

13 – Canine 

14 – First premolar

15 – Second premolar

16 – First molar

17 – Second molar

18 – Third molar

Second Quadrant

21 – Central incisor

22 – Lateral incisor

23 – Canine 

24 – First premolar

25 – Second premolar

26 – First molar

27 – Second molar

28 – Third molar

Third Quadrant

31 – Central incisor

32 – Lateral incisor

33 – Canine 

34 – First premolar

35 – Second premolar

36 – First molar

37 – Second molar

38 – Third molar

Fourth Quadrant

41 – Central incisor

42 – Lateral incisor

43 – Canine 

44 – First premolar

45 – Second premolar

46 – First molar

47 – Second molar

48 – Third molar

Baby teeth: There are 5 baby teeth present in each quadrant

First Quadrant

51 – Central incisor

52 – Lateral incisor

53 – Canine 

54 – First molar

55 – Second molar

Second Quadrant

61 – Central incisor

62 – Lateral incisor

63 – Canine 

64 – First molar

65 – Second molar

Third Quadrant

71 – Central incisor

72 – Lateral incisor

73 – Canine 

74 – First molar

75 – Second molar

Fourth Quadrant

81 – Central incisor

82 – Lateral incisor

83 – Canine 

84 – First molar

85 – Second molar


The set of teeth in humans comprise of incisors, canines, premolars and molars.  Children get all their 20 primary teeth by the age of 3 years. By the age of 21 years, most people will get their wisdom teeth and have all their 32 permanent teeth.

Teeth are vital for chewing and speaking. Maintenance of good oral hygiene is essential to keep the teeth healthy and to function throughout life.

A good and healthy oral hygiene can be maintained by:

  • Brushing teeth twice a day, daily.
  • Flossing once a day
  • Rinsing after every meal
  • Avoiding excess sugar in food
  • Visiting your dentist every 6 months

Additional References

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