Embryology of Tooth Development 1 - 2.2 PDF
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Summary
This document explains the stages of tooth development. It details the developmental stages of primary teeth and permanent teeth, including the initiation, bud, cap, and bell stages, and discusses molecular interactions, and processes such as morphodifferentiation and potential issues like oligodontia and macro/microdontia.
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**[Embryology of tooth development 1 - 2.2]** 6th week = primary teeth 14th week = permanent teeth Heterodontal dentition - - - - - - - -  **[Stages of development]** 1. 2. 3. Dental lamina = arch shaped band of tissue which follows link of vestib...
**[Embryology of tooth development 1 - 2.2]** 6th week = primary teeth 14th week = permanent teeth Heterodontal dentition - - - - - - - -  **[Stages of development]** 1. 2. 3. Dental lamina = arch shaped band of tissue which follows link of vestibular fold and by 8th week swellings develop on deep surface **Tooth germ** - - -   Shh Ectopic Shh = ectopic tooth thickening No Shh signalling = arrest of tooth development Wnt/Shh interactions control dental epithelium boundaries GLI = transcription factor  **Molecular info for tooth type** - - -   **Mesenchymal odontogenic homeobox gene code**  Molecular mechanisms in morphogenesis - - -    **[Primary teeth ]** **Crown development** Initiation - 6th week 1. 2. 3. 4.  Potential issues: oligodontia (partial anodontia), supernumeraries 5. 6. Bud stage - 8th week - - - - Potential issues: macro/microdontia - - - → forms Cap  Cap stage - 9-11th week - - - - Dental papilla = condensation of ectomesenchymal cells around invagination of cap and is surrounded by follicle and sac Dental sac/follicle = ectomesenchymal cells around papilla and enamel organ 1. 2. **A -- Stellate reticulum** **B -- External enamel epithelium** **C -- Internal enamel epithelium** **D -- Dental papilla** **E -- Dental follicle** Bell stage - 11-12th week - - - -  Appositional/ late bell stage and enamel maturation 18th week - Morphodifferentiation (crown shape determined) - - - Potential issues: enamel/dentine dysplasia Dental lamina disintegrates - may leave epithelial pearls **Transitionary structures** - - - - - - - - - - - **Root development** 1. 2. 3. 4. PDL and alveolar bone Dental follicle cells → fibroblasts and osteoblasts **Permanent teeth** 14th week = All teeth (except molars) - Successional lamina extends form tooth bud 20th week = Molars - dental lamina in posterior part of oral cavity form tooth buds which undergo same stages of dev a primary teeth **Treacher Collins syndrome** - -
