Primary Dentition

Humans are born with two sets of dentition – deciduous or primary dentition and permanent dentition.

The primary dentition is the first set of dentition in a person’s life and consists of 20 teeth. It develops during the embryonic stage of development and erupts in the mouth during infancy.

The primary teeth erupt and shed on a schedule, and there are many factors which can influence the eruption.

Parents always anticipate their child’s teeth and therefore, as parents you should know what to expect when your children are going to have their first teeth.

What are the primary teeth?

Primary teeth are the first set of dentition that erupts in a person’s mouth. It comprises of 20 teeth- 4 central incisors, 4 lateral incisors, 4 canines, and 8 molars.

They are usually lost and replaced by permanent teeth, which happens according to a schedule.

Eruption Schedule for Primary and Permanent teeth

Primary Teeth Eruption Chart

UPPER TEETH ERUPT SHED
Central Incisor

Lateral incisor

Canine

First Molar

Second Molar

8-12 months

9-13 months

16-22 months

13-19 months

25-33 months

6-7 years

7-8 years

10-12 years

9-11 years

10-12 years

LOWER TEETH ERUPT SHED
Central Incisor

Lateral Incisor

Canine

First Molar

Second Molar

6-10 months

10-16 months

17-23 months

14-18 months

23-31 months

6-7 years

7-8 years

9-12 years

9-11 years

10-12 years

Permanent Teeth Eruption Chart

UPPER TEETH ERUPT
Central Incisor

Lateral Incisor

Canine

First Premolar

Second Premolar

First Molar

Second Molar

Third Molar

7-8 years

8-9 years

11-12 years

10-11 years

10-12 years

6-7 years

12-13 years

17-21 years

LOWER TEETH ERUPT
Central Incisor

Lateral Incisor

Canine

First Premolar

Second Premolar

First Molar

Second Molar

Third Molar

6-7 years

7-8 years

9-10 years

10-12 years

11-12 years

6-7 years

11-13 years

17-21 years

 

Functions of Primary teeth

Primary teeth are essential in the development of the mouth. The primary teeth maintain the arch length within the jaw and the bone. The permanent teeth replacements develop from the same tooth germs as the primary teeth.

The primary teeth provide guides for the eruption pathway of the permanent teeth. They also help in the development of muscles of the jaw and the formation of the jaw bones by maintaining proper space for permanent teeth.

The roots of primary teeth provide an opening for the permanent teeth to erupt. They also help in the development of a child’s speech and chewing food.

Importance of primary teeth

Some parents still consider that primary teeth are not as vital as they eventually fall and are replaced by permanent teeth. This is not correct as primary teeth are essential on their own. (1)

Healthy primary teeth are important for eating, smiling, talking and guiding permanent teeth into place. Early neglect of primary teeth can result in several problems.

Tooth decay in young children can quickly lead to pain and infection, and dental treatment in young children is difficult and risky. (2)

If primary teeth are lost prematurely, the space available for permanent is reduced, resulting in crowding or misalignment of permanent teeth. Children who experience tooth decay in primary teeth are at higher risk of developing tooth decay in permanent teeth. (3)

So, it’s important for parents to establish good oral habits for their children at an early age.

Factors Influencing Eruption

Teething in children is equally anticipated and feared by every parent. If you are one of these parents, these factors can help you estimate the emergence of primary dentition:

  • The eruption of teeth is earlier in girls than boys, except for the first molars.
  • The teeth in lower jaw erupt before that in the upper jaw.
  • Children with height shorter than average have delayed eruption.
  • People living in warmer regions have an earlier eruption of teeth than those living in colder areas.
  • People living in urban areas appear to get their teeth earlier than those in rural areas.
  • People with a disadvantaged social background may experience delayed eruption.
  • A child’s rank in the family affects the eruption of teeth- younger children get teeth later than older children.

Primary teeth disorders

Disorders are common at any age and can be seen in primary teeth too. Problems in primary teeth are commonly eruption-related disorders. Some of these disorders are as follows:

  • The early eruption of teeth- it usually applies to the individual tooth. However, if multiple teeth erupt prematurely, it may indicate hyperthyroidism.
  • Premature eruption- This is seen when immature teeth erupt still in their bud form. It can be a result of infection or trauma to the mouth. (4)
  • Impacted primary tooth
  • Eruption cyst-it is an oval, bluish sac containing fluid that forms on top of an erupting tooth.

Over to you

It is a joy for many parents to see their child’s first tooth erupt. Primary teeth or milk teeth are just as important as permanent teeth, so parents should establish the importance of good oral habits.

You should know all about primary dentition so you can help your children achieve a healthy smile and keep it for their whole life.