Shedding of Deciduous Teeth

Questions and Answers

What is the main reason for the loss of deciduous teeth?

Eruption of permanent teeth

Resorption of their roots (correct)

Increase in muscle power

Growth of the jaw

At what age does the emergence of the first permanent tooth occur?

6 months old

12 years old

6 years old (correct)

6 weeks old

What is the mechanism of shedding of deciduous teeth?

Pressure of the succeeding permanent teeth (correct)

Action of osteoblast

Action of odontoblast

Action of fibroblast

Where does the resorption of deciduous teeth start in anterior teeth?

Lingual side Signup and view all the answers

What happens to the roots of deciduous teeth during shedding?

They are resorbed Signup and view all the answers

When does the resorption of deciduous molars occur?

Long before they are shed Signup and view all the answers

What is the purpose of shedding of deciduous teeth?

To allow for the eruption of larger permanent teeth Signup and view all the answers

What is responsible for the resorption of PDL during shedding?

Fibroclast Signup and view all the answers

What is the first step in the shedding of posterior deciduous teeth?

Pressure from successional teeth Signup and view all the answers

What type of cells are responsible for resorbing bone and dentin during tooth shedding?

Odontoclasts Signup and view all the answers

What is the main function of fibroclasts during tooth shedding?

Resorption of periodontal ligament Signup and view all the answers

What type of cells are responsible for resorbing bone during tooth shedding?

Osteoclasts Signup and view all the answers

What is the term used to describe the abnormal resorption of dental hard tissue?

Pathological resorption Signup and view all the answers

What is the origin of odontoclasts?

Circulating monocytes Signup and view all the answers

Study Notes

Shedding of Teeth

Shedding or exfoliation is the normal physiological process of eliminating deciduous teeth.
The loss of deciduous teeth is mainly due to the resorption of their roots.

Need of Shedding

With the growth of a child, the jaw grows, but the deciduous teeth cannot.
The muscle of mastication increases in size and power of contraction.
The PDL of deciduous teeth cannot withstand the masticatory forces.

Rules of "Sixes" in Dental Development

6 weeks old in utero: beginning of dental development
6 months old: emergence of the first primary tooth
6 years old: emergence of the first permanent tooth

Mechanism of Shedding

Pressure of the succeeding permanent teeth
Increase in force of mastication
Action of odontoclast (cementoclast for cementum and dentinoclast for dentin)
Action of osteoclast, which resorbs bone
PDL is resorbed by fibroclast

Pattern of Shedding

Anterior Teeth

Resorption of deciduous teeth starts from the lingual side
Later developing tooth occupies a position directly apical to deciduous teeth

Posterior Teeth

Resorption of deciduous teeth begins on the inner surface of the roots of molar
Resorption occurs long before the deciduous molars are shed

Process of Shedding

First step: pressure from successional teeth
Leads to activation of osteoclast, odontoclast, and fibroclast

Osteoclasts

Bone-resorbing cells derived from the monocyte-macrophage lineage
Giant multinuclear cells with 4-20 nuclei
Resorb hard tissue by separating mineral from the collagen matrix through the action of hydrolytic enzymes
Resorption occurs at the ruffled border, which greatly increases the surface area of the osteoclast in contact with bone