3a odontogenesis Flashcards
What does the dental follicle give rise to?
cells of tooth support
- cementoblasts - form cementum
- fibroblasts - form PDL collagen fibres
- osteoblasts - form bone alveolar
what induced odontoblast formation in the root?
HERS
Pre-dentine then dentine forms, HERS basal lamina breaks down, what do the HERS cells secrete?
enamel matrix proteins (amelogenins) on to the pre dentine surface
HERS secrete enamel matrix proteins what do they mineralise to form?
the hyaline layer (of hopewell smith)
when cementum matrix mineralises, what does it trap?
PDL fibres
what is the epithelial signal to dental follicle cells to migrate down to the root surface and form cementoblasts?
HERS
What do the remnants of HERS form?
Cell rests of malassez in the PDL - they have cystic potential
Where is the hyaline layer (of hopewell-smith)?
between dentine and cementum
What is the role of the hyaline layer of hoepwell-smith?
- induce cementoblast formation
- cement cementum to the tooth
what are the 2 types of cementum?
cellular (secondary) and acellular (primary)
What type of cementum is formed when it is laid down quickly?
cellular - cementoblasts are trapped in the cementum
What are the 3 layers of the dental follicle?
- inner investing layer - vascular, becomes cementoblasts
- loose connective tissue layer
- outer layer - lines alveolus with bone
what layer of the dental follicle does the alveolar bone come from?
the outer layer of condensed mesenchyme (dental follicle)
What are the main cell found tyep found in the PDL?
spindle-shaped fibroblasts
what do PDL fibroblasts produce?
Collagen fibres, hyaluronan, growth factors (TGFbeta 1 , EGF and MMP
