Dental Embryology Sergiu

memory's version from 2016-04-08 21:14

Section 1

Question Answer
The enamel organ will give rise toenamel
The dental sac will give rise tocementum, PDL, alveolar bone proper
The dental papila will give rise todentin and pulp
By the end of cap stage:the tooth germ is complete and consists of 1)enamel organ, 2) dental sac, 3) dental papila
Acellular cementum:coronal two thirds of the root
Cellular cementum=Apical third of the root
Dental Lamina is a:U shaped tissue that arises from oral epithelium and from wich the jaws will develop
Intertubular dentin=the dentin found between the dentinal tubules
Bud stageDental Lamina penetrates into ectomesenchyme
Peritubular dentin=is formed inside the walls of the dentinal tubules
Cap stage:Enamel organ forms+Dental papilla+Dental sac=Tooth germ
Tooth germ=Enamel organ+Dental papilla+Dental sac
Pulp capping is more succesful in young or old teeth ???Young teeth
Bell stage;Ameloblasts, Odontoblasts, Cementoblasts, fibroblasts start to appear and differentiate
Apposition=Specialized cells start to deposit dental tissues:enamel, dentin, pulp, cementum
The enamel organ is derived from ectoderm and has:4 layers:1) Outer enamel epithelium 2) Inner enamel epithelium 3)Stratum intermedium 4) Stratum reticulum
The enamel organ is derived from ectoderm

Section 2

Question Answer
The dental papila and dental sac are derived frommesenchyme
From Inner Enamel Epithelium develops the:Enamel Matrix (near the forming DEJ)
Mature enamel consists of:96% of inorganic matter, 1% organic matrix and 3% water
Chemical formula of Calcium HydroxyapatiteCa10(PO4)6(OH2)
Architecture of pulp: Odontogenic Zone (Odontoblasts)--->Cell free zone--->Cell rich zone--->Plexus of RaschkowTrue
Architecture of pulp: Odontogenic Zone (Odontoblasts)--->Cell rich zone--->Cell free zone--->Plexus of RaschkowFalse
Nerve fibers in pulp:Afferent (Sensory) Fibers + Autonomic Nerve Fibers
Gemination and Fusion ocur during;Cap stage
Cementum exhibits (are) Sharpey's fibers ???True (they are inserted into the outer part of the cementum at 90 degrees)

Section 3

Question Answer
Congenital absence of teeth (Anodontia) and supranumerary teeth result result from an interruption in ____________ phaseInitiation
Induction is the main process in:Initiation (6-7 week, Dental Lamina appears)
Proliferation is the main process in:Bud stage 8 week
Proliferation, Differentiation, MorphogenesisCap stage 9-10 week
Dens in dente, gemination, fusion, and tubercle formation occur this phase;Cap stage 9-10 week
Gemination and Fusion ocur during;Cap stage 9-10 week
Histodifferentiation and MorphodifferentiationBell stage 11-12 week
Macrodontia/Microdontia ocuur duringBell stage 11-12 week
Enamel dysplasia, concrescence, enamel pearls occur during;Apposition
Cells begin to deposit specific dental tissues-enamel, dentin, cementum...Aposition
Primary dentin=Dentin formed before the completion of the apical foramen of the root
Secondary dentin=Dentin formed after completion of the apical foramen
Tertiary dentin=Dentin formed very rapidly in localized regions in response to a localized to exposed dentin
When dentin is damaged, odontoblastic processes die or retract, leaving empty dentinal tubules calledDead tracts and appear as dark areas
With time, the dead tracts can become filled with mineral and are calledBlind tracts and appear as white sections

Section 4

Question Answer
3-d week=Stomodeum appears
6-7 week=Dental lamina appears
8 week=Bud stage
9-10 week=Cap stage
11-12 week=Bell stage
Bell stage is followed by=Aposition + Calcification +Eruption + Atrition