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所在平台: Udemy |
课程主页: https://www.udemy.com/course/oral-histology-part-1/
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本课程“口腔组织学基础”A-Z第一部分，主要介绍了口腔组织学课程的入门知识和术语。课程从胚胎发育的第五、六周开始，重点讲解牙齿发育（牙发生）的过程。 牙齿发育是一个涉及复杂生物学过程的体系，主要由两部分组织构成： 1. **外胚层**：形成口腔上皮（复层鳞状上皮）。 2. **外胚间充质**：由中胚层结缔组织和神经嵴细胞组成。 这两种组织的相互作用，最终促使20颗乳牙和32颗恒牙的形成。所有牙齿的基本发育过程是相似的。 **牙齿发育的阶段**： 1. **开始期（牙板形成）**：由口腔上皮基底层细胞增生，向下方间充质延伸形成一个带状结构，称为牙带或牙板。这是位于未来颌骨上的胚层。 2. **牙蕾期（开始期）**：在胚胎发育的第八周开始，牙板细胞大量增殖形成芽状结构，每个未来颌骨中有十个卵圆形的芽状结构开始向周围外胚间充质凹陷，这些将发育成乳牙。 3. **牙帽期（增殖期）**：在胚胎发育的第九至第十周开始，细胞继续增殖，但在牙芽的不同部位增殖速度不均，形成一个覆盖在外胚间充质上的三维帽状结构。 4. **早期钟状期（组织和形态分化）**：随着釉器凹陷加深，呈现出钟状，称为早期钟状期。一旦第一层牙本质形成，就进入晚期钟状期。在此阶段，牙冠的最终形态（形态分化）得以确定。形成牙冠硬组织的细胞，如形成釉质的釉母细胞和形成牙本质及牙髓的成牙本质细胞，也完成了其组织分化。
ORAL HISTOLOGY COURSEIntroduction and terminology The process of tooth development begins around week 5-6. Intrauterine life. primitive oral cavity- stomodeum -Tooth Development ( Odontogenesis ) The Development Of The Tooth Involves Many Complex Biologic Processes, Including 1- Ectoderm - Oral Epithelial (Stratified Squamous) 2- Ecto-mesenchymal (mesoderm C.T +Neural Crest). From This Interaction 1- 20 Deciduous - Labial to the dental lamina 2- 32 Permanent Teeth Develop. lingual to the dental lamina The Fundamental Developmental Process Is Similar For All Teeth.Crown formationDEVELOPMENTAL STAGES 1- Initiation stage (dental lamina ): It is formed by proliferation of the basal cell layer of the oral epithelium in the underlying mesenchyme forming a band called tooth band or dental lamina.- Germal Layer - On The U Future Jaws 2- ( Bud stage ) - initiation stage: This stages starts at the beginning of eight week of prenatal development. It involves extensive proliferation of the dental lamina into buds. In each future jaw, ten oval buds start to penetrate into the surrounding ectomesenchyme. that will later form the primary teeth. 3- Cap Stage ( Proliferation stage ) This stage starts between the ninth and tenth week of prenatal development. During this stage, proliferation of cells continues, but in unequal manner in different parts of the tooth bud, resulting in the formation of a three-dimensional cap shape overlying the ectomesenchyme. 4- early-bell Stage (histo & morpho-differentiation) The enamel organ assumes a bell shape due to invagination of enamel organ which becomes deeper and called as early bell stage. Once the first layer of dentin , it becomes late bell stage. In this stage, the crown of the tooth gets its final shape (morpho-differentiation). the cells that form the hard tissues of the crown the ameloblasts that form the enamel ) ( the odontoblasts that form dentin and pulp) acquire histo-differentiation.
