Chapter 5 Development of Teeth Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Development of Teeth: Learning Objectives  After reading this chapter, the student will be able to:  Describe the origin of the tooth formative cells and the role of induction in tooth formation.  Describe the stages of tooth formation and the mineralization of enamel and dentin.  Describe the development of the tissues that surround the developing teeth. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 2

Development of Teeth  Initiation of tooth development  Stages of tooth development  Development of the dental papilla  Dentinogenesis  Amelogenesis  Crown maturation  Development of the tooth root  Development of supporting structures Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 3

Development of Teeth Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 4

Initiation of Tooth Development  Ectodermal cells form the enamel organ.  Mesenchymal cells form the dental papilla. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 5

Initiation of Tooth Development Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 6

Initiation of Tooth Development Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 7

Stages of Tooth Development: Bud and Cap Stages Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 8

Stages of Tooth Development: Bell Stage Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 9

Stages of Tooth Development: Bell Stage Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 10

Dentinogenesis Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 11

Dentinogenesis Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 12

Dentinogenesis Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 13

Dentinogenesis Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 14

Amelogenesis Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 15

Amelogenesis Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 16

Amelogenesis Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 17

Amelogenesis Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 18

Amelogenesis Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 19

Amelogenesis Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 20

Amelogenesis Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 21

What is amelogenesis imperfecta?  Amelogenesis imperfecta is a genetic problem in which the enamel is poorly developed and mineralized. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 22

Crown Maturation Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 23

Crown Maturation Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 24

Development of the Tooth Root: Root Sheath Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 25

Development of the Tooth Root: Root Sheath Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 26

Development of the Tooth Root: Single Root Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 27

Development of the Tooth Root: Single Root Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 28

Development of the Tooth Root: Multiple Roots Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 29

Development of the Tooth Root Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 30

Development of Primary and Permanent Teeth  Formation of which tooth, primary or permanent, do you think would take the least amount of time? Why?  When do primary teeth begin development?  What factors can affect primary teeth development?  When do permanent teeth begin development?  What factors can affect permanent teeth development? Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 31

Development of Primary and Permanent Teeth Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 32

Development of Supporting Structures Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 33

Development of Supporting Structures: Periodontal Ligament Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 34

Development of Supporting Structures: Alveolar Process Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 35

Summary  Tooth development involves the interaction of epithelial and mesenchymal tissues.  Stages of soft tissue development include bud, cap, and bell.  Stages of hard tissue development include dentinogenesis and amelogenesis.  Root formation follows crown development.  Each stage includes morphologic changes in shape and side coordinated with microscopic changes in cell shape and function. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 36

Review Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 37