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Stack #28680
Question | Answer |
---|---|
Initiation stage period | 6-7th week |
Bud Stage period | 8th wk |
Cap Stage period | 9-10th wk |
Bell Stage period | 11-12th wk |
Apposition Stage period | Varies per tooth |
Maturation Stage period | Varies per tooth |
Initiation description | Ectoderm lining of stomodeum gives rise to oral epithelium and then to dental lamina, adjacent to deeper ectomesenchyme, which is influenced by the neural crest cells. Both tissues are separated by a basement membrane |
Bud stage description | Growth of dental lamina into bud that penetrates growing ectomesenchyme |
Cap stage description | Enamel organ forms into cap, surrounding mass of dental papilla from the ectomesenchyme and surrounded by mass of dental sac also from the ectomesenchyme. Formation of the tooth germ |
Bell stage description | Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types |
Apposition stage description | Dental tissues secreted as matrix in successive layers |
Maturation stage description | Dental tissues fully mineralize to their mature levels |
Enamel embryological background | Enamel organ |
Enamel tissue type | Epithelial |
Formative cells of enamel | Ameloblasts |
Incremental lines of enamel | lines of Retzius |
Mature cells of enamel | None-lost with eruption |
Resorptive cells of enamel | odontoclasts |
Inorganic mineral levels-enamel | 96% |
Organic/water levels-enamel | 1% organic and 3% water |
Tissue formation after eruption-enamel | None |
Enamel vascularity | None |
Enamel innervation | None |
Dentin embryological background | Dental papilla |
Tissue type for dentin | Connective tissue |
formative cells of dentin | Odontoblasts |
Incremental lines of dentin | Imbrication lines of von Ebner |
Mature cells of dentin | Only dentinal tubules with processes |
Resorptive cells of dentin | Odontoclasts |
Inorganic mineral levels of dentin | 70% |
Organic/water levels-dentin | 20% organic 10% water |
Dentin tissue formation after eruption ? | Possible |
Vascularity of dentin? | none |
Innervation of dentin? | Present |
Cementum embryological background | Dental papilla |
Cementum tissue type | Connective tissue |
Cementum formative cells | Cementoblasts |
Cementum incremental lines | Arrest and reversal lines |
Cementum mature cells | Cementocytes |
Resorptive cells of cementum | odontoclasts |
Cementum inorganic levels | 65% |
Cementum organic/water levels | 23% organic 12% water |
Cementum tissue formation after eruption? | possible |
Vascularity of cementum? | none |
Cementum innervation? | None |
Alveolar bone embryological background | Mesoderm |
Alveolar bone tissue type | Connective tissue |
Alveolar bone formative cells | osteoblasts |
Alveolar bone incremental lines | Arrest and reversal |
Alveolar bone mature cells | Osteocytes |
Alveolar bone resorptive cells | Osteoclasts |
Alveolar bone inorganic levels | 60% |
Alveolar bone organic and water levels | 25% organic 15% water |
Alveolar bone tissue formation after eruption? | possible |
Vascularity of alveolar bone? | present |
Innervention of alveolar bone? | present |
Influence ectodermal tissues in order for initiation of odontogenesis | Mesenchymal tissues |
Tissue lining stomodeum | Ectoderm |
Outer portion of ectoderm gives rise to | Oral epithelium |
Acellular structure separates oral epithelium and ectomesenchyme in stomodeum | Basement membrane |
spithelium grows deeper into the ectomesenchyme and induced to produce this layer during 7th wk | Dental lamina |
Dental lamina begins initially to form in the midline for | both arches and progresses posteriorly |
This stage is named for an extensive proliferation/growth of dental lamina into buds penetrating into the ectomesenchyme | Bud Stage |
At the end of proliferation process involving dental lamina | both future maxillary arch and mandibular arch will each have 10 buds |
In the bud stage the basement membrane is between | the bed and growing ectomesenchyme |
In bud stage each bud from dental lamina with surrounding ectomesenchyme | develop into a tooth germ |
all teeth and associated tieeues develop from | ectoderm and mesenchymal tissue |
ectoderm and mesenchymal tissue | ectomesenchyme |
development of all teeth and associated tissue is influenced by | neural crest cells |
Only this process of the ectoderm and mesenchymal tissues occurs in the bell stage | Proliferation |
In areas where teeth will not be forming | dental lamina only remains thickened |
non-tooth-producing portion of the dental lamina | disintegrates as the developing oral mucosa comes to line the oral cavity |
3 components of tooth germ | Enamel organ, Dental papilla, Dental sac |
Enamel Organ | Produces enamel |
Physiological process (5 stages of growth) | Induction, Proliferation, Differentiation, Morphogenesis, Maturation |
Induction Stage | - Interaction between embryolocical tissues |
Proliferation Stage | - Controlled cellular growth |
Differentiation Stage | - Change in embryonic cells, Specialized cells do different jobs |
Morphogenesis Stage | - Process of development of specific tissue morphology |
Maturation Stage | - Hard dental tissues are fully calcified, Fully developed |
Stages of Odontogenesis | - Initation Stage, Bud Stage, Cap Stage, Bell Stage, Apposition |
Dental Lamina Produces forms what? | - Midline if each arch and progresses posteriorly |
Initiation stage of Odontogenesis produces which layer? | Dental Lamina |
The physiological process of proliferation occurs in which stage? | Bud Stage |
During the Bud Stage | - Growth of dental lamina into buds or oval masses occurs |
Penetration of the growing ectomesenchyme is by the | Buds |
Future arches have how many buds each? | 10 buds per arch |
Each tooth bud from dental lamina will develop into what? | - A tooth germ and its associated supporting tissues:o Enamel organ, Dental papilla, Dental sac |
Which stage occurs between the 9th and 10th week of prenatal development? | Cap Stage |
What physiological processes are the cap stage derived from? | - Proliferation, differentiation, morphogenesis |
Which physiological process is the predominant process in the cap stage? | morphogenesis |
What occurs during the cap stage? | - Unequal growth in different parts of the tooth bud |
In the cap stage | - Formation of cap shape attached to dental lamina |
The Bud is an actual cell tooth germ in this stage | Cap stage |
The depression in the deepest part of the tooth bud forms what and in what stage? | - The enamel organ in the cap stage |
Within the concavity of the cap of enamel organ, the inner mass of ectomesenchyme is called? | - Dental Papilla (Cap stage) |
The basement membrane between the enamel organ and dental papilla is the future site of? | DEJ |
Remaining ectomesenchyme on the outside of the enamel organ condenses into? | Dental Sac |
At the end of the cap stage, the enamel organ, dental papilla, and dental sac are referred to as? | Tooth Germ |
Initiation for permanent anterior teeth is at which week? | the 10th week in the cap stage |
Successional dental lamina will forms what? | - succedaneous teeth (permanents) |
Primary dental lamina develops an extension off of each tooth bud on the lingual side is called? | - Successional dental lamina |
Which teeth develop from posterior extensions of dental lamina distal to the primary 2nd molar’s dental lamina? | - Permanent molars (non succedaneous) |
Tooth germ forms during which stage? | - Cap stage |
The rest of the cells not in the dental concavity are in? | - The dental sac |
Which stage occurs between the 11th and 12th week of prenatal development? | - The bell stage |
The physiological processes that occur in the Bell stage are? | - proliferation, differentiation, and morphogenesis |
The predominant physiological process that occurs in the Bell stage is? | - Differentiation |
During the Bell stage | - The cap shape of enamel organ assumes a bell shape |
What are the different types of cells found in the enamel organ? | - Outer enamel epithelium(OEE), Inner enamel epithelium(IEE), Stellate reticulum, Stratum intermedium |
Small cuboidal cells, one cell layer thick that outline the shape of the enamel organ | - Outer enamel epithelium (OEE) |
Innermost tall columnar cells on the concave side, one cell layer thick | - Inner enamel epithelium (IEE) |
IEE cells differentiate into | - Ameloblasts |
Outer star-shaped cells, many layers thick that fill and form a network in the enamel organ | - Stellate reticulum |
Stellate reticulum cells are responsible for | - production of enamel matrix; protection for IEE and nourishment of stratum intermedium |
Stellate reticulum are located inbetween which two cells | - OEE and IEE |
Inner compressed layer of flat to cuboidal cells | - Stratum intermedium |
Stratum intermedium is the layer between which two cells? | - Stellate reticulum and IEE |
The job of the stratum intermedium is to? | - Produce enamel matrix |
Stratum intermedium provide nourishment for? | - IEE and ameloblasts |
The two types of tissues/layers in the Dental papilla are? | - Outer cells and Central cells |
Outer cells are peripheral cells that differentiate into? | - odontoblasts (form dentin) |
Central cells are inner cells that differentiate into? | - Pulp tissue |
Final stage of odontogenesis | - Apposition stage |
During the apposition stage what occurs? | - Enamel, dentin, and cementum are secreted in matrix and then into layers |
Maturation is reached when? | - dental tissues become fully mineralized |
In the apposition stage what is necessary for production of enamel, dentin, and cementum? | - Interactions between enamel organ, dental papilla and dental sac |
This cell elongates as it differentiates into premeloblasts | - IEE cells |
These cells induce outer cells of dental papilla to differentiate into odontoblasts | - Preameloblasts |
These cells begin dentinogenesis or predentin | - Odontoblasts |
Dentinogenesis is | - The apposition of dentin matrix |
Odontoblasts start the matrix activity before | - enamel matrix production begins |
This is found between preameloblasts and odontoblasts and disinegrates | - Basement membrane |
During the apposition stage this cell is in contact with newly formed predentin | - Odontoblasts |
What causes preameloblasts to differentiate into ameloblasts | - Odontoblasts being in contact with predentin |
Amelogenesis is | - The apposition of enamel matrix |
Disintegration of the basement membrane forms what? | - The DEJ |
Disintegration of the basement membrane cases what? | - Preameloblasts to differentiate into ameloblasts |
This takes place after the crown is completely shaped and the tooth is starting to erupt into the oral cavity? | - Root development |
The OEE and the IEE combine together at the most cervical portion of enamel organ is called? | - Cervical loop |
The cervical loop is responsible for? | - root development |
Cervical loop grows deeper into the enamel sac, elongates, and moves away from the crown area and encloses more of the dental papilla tissue to form | - Herwig’s epithelial root shealth(HERS) |
The function of HERS is | - to shape the roots and induce dentin formation in root area |
HERS is located between | - dental papilla and dental sac |
IEE of HERS differentiate and become | - odontoblasts |
Odontoblasts from the IEE of HERS form what? | - Root dentin |
Odontoblastic differentiation occurs due to a | - Lack of stellate reticulum and stratum intermedium layers |
What occurs when root dentin is completed? | - Basement membrane of HERS disintegrates |
After the disintegration of HERS its cells may become what? | - epithelial rests of Malassez |
Rests of Malassez is a group of cells located in? | - mature periodontal ligament |
Rests of Malassez cells may cause problems by becoming what? | - cystic |
Cap Stage of Odontogenesis | - Tooth bud of dental lamina grows into cap shape |
Bell Stage of Odontogenesis | - Differentiation occurs and enamel organ assumes bell shape |
Apposition Stage of Odontogenesis | - Layered formation of hard tissue |