histology of Tooth Development

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Stages of Tooth Development

• Dental lamina

• Bud

• Cap

• Bell

• Appositional

• Repeated by Successional lamina

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Early Dental Lamina

Tongue Dental lamina Vestibular laminarxdentistry.net

Bud Stagerxdentistry.net

Cap Stage of Tooth

Development

Dental (enamel) organ

Dental papilla

Dental follicle

©Copyright 2007, Thomas G. Hollinger, Gainesville, Flrxdentistry.net

Cap Stage

©Copyright 2007, Thomas G. Hollinger, Gainesville, Flrxdentistry.net

Bell Stage

Oral Histology, 5th edition, A R Ten Cate

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Structures Seen at Bell Stage

Oral cavity

Outer dentalepithelium

Dental lamina

Enamel knob

Stellate reticulum

Stratum intermedium

Inner dental Epithelium

Dental papilla

©Copyright 2007, Thomas G. Hollinger, Gainesville, Fl

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Cervical Loop

Acellular zone

Preameloblasts(IDE or IEE)

Stratum intermedium

Stellate reticulum

ODE (OEE)

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Structures of the Dental

Organ

Dental papilla

IDE

Dental follicle

Dental organ

ODE

Stellatereticulum

Stratumintermedium

Cervical loop

Acellular zone

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Appositional Stage

Oral Histology, 5th edition, A R Ten Cate

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Structures at Appositional Stage

Dental follicle

ODE

Stellate reticulum

IDE

Pulp

Odontoblasts

Stratum intermedium

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Dentinogenesis

Oral Histology, 5th edition, A R Ten Cate

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Details of Tooth

Development

Cell free zone

Odontoblasts

Ameloblasts

Preameloblasts

Preodontoblasts

Acellular zone

Ameloblast with

Tomes process

Oral Histology, 5th edition, A R Ten Cate

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Incorporation of Tetracycline

during Dentinogenesis

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Oral Histology, 5th edition, A R Ten Cate

Some Types of Dentin

Mantle dentin

Tertiary dentin

Primary dentin

Secondary dentin

Predentin

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Amelogenesis

• Enamel proteins– Amelogenins (Bulk of proteins)– Tuftelin (Just at the DEJ)– Enamelin 2%– Amelins/Ameloblastins 5-10%

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Early Apposition

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Distal End of a Ameloblast

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Distal End of a Ameloblast

Forms enamel rod

Forms rod sheath

Distal process

Proximal portion of processJunctional complex

Formsinterrod substance

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Tomes’ Process

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Secretory Ameloblast

Enamel

Tomes’ process

Cell body of ameloblast

Junctional complex

Oral Histology, 5th edition, A R Ten Cate

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Grazing Section through Forming

Enamel

Interrod substance forms first to establish a mold for the enamel rod

Terminal bar (in TEM one sees the junctional complex)

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Developing Enamel

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Root Formation Cervical loop forms the epithelial

root sheath (of Hertwig)

Cervical loop

Dental papilla

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Root Formation

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PDL, Cell Rests, and Cementum

Cell rest (of Malassez)

Cells of the dental follicle (forms cementocytes)

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Granular Layer of Tomes

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Cellular Cementum

Acellular cementum

Cellular cementum

Hyaline layer (of Hopewell Smith)

Granular layer of Tomes

Dentin (with tubules)

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Junctional Epithelium

“Basement membrane” shown in green

B = Alveolar mucosa

C = Sulcular epithelium

D = Basement membrane of junctional epithelium (derived from the reduced enamel epithelium)

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Thanx. !!