OCB02-1015 Amelogenesis Flashcards
What is amelogenesis?
The formation of enamel on teeth and begins when the crown is formed during the advanced bell stage of tooth development after dentinogenesis
Wha are the two tyes of matrix proteins secreted by ameloblasts?
amelgoenins and non-amelogenins
What part of the ameloblast secretes the matrix proteins?
Tomes process
What happens to the size of the ameloblast as maturation proceeds?
Ameloblasts become shorter
What forms in mineralisation?
Hydroxyapatite crystals
What shape are ameloblasts?
Tall columnar cells
How do ameloblasts trigger the formation of odontoblasts?
When ameloblasts are formed hey send signalling proteins across the EDJ which trigger cytodiffrentiation of odontoblasts in the dental papilla to form dentine
Where does the nucleus of the ameloblast move too?
The proximal end
What happens to the stellate reticulum as amelogenesis starts? and what does this cause?
It collapses
This brings the OEE closer the the ameloblasts and the OEE is highly vascularised which supplies nutrients to ameloblasts so it can synthesise matrix proteins
How long will matrix secretion for a permanent molar take?
4-7 years
What happens to the first layer of enamel when it is secreted onto the dentine
It mineralises immediately and doesn’t contain enamel rods
Are matrix proteins collagenous?
They are not collagenous
What are the non-amelogenins?
Ameloblastin
Tuftelin
Enamelin
What is the crystal structure?
Ca10 [PO4]6[OH]2
Where does crystal growth occur from?
Tommes’ Process
