Enamel

Questions	Answers
In which stage of amelogenesis does resoprtion of basal lamina of inner enamel epithelium occur	Presecretory stage. During histodifferentiation.
In which stage of amelogenesis  does initial layer of aprismatic enamel forms	Secretory stage. This event marks the start of secretory stage
In which stage of amelogenesis does, ameloblast dies?	In late secretory stage and the transition stage where morphologically most of ameloblasts shorten while 50% of them die
In which stage of amelogenesis does vascular invagination of enamel organ occur	In transition stage
In which stage of amelogenesis does the basal lamina of ameloblast reformed	In transition stage
In which stage of amelogenesis does matrix secretion ceases	In transition stage
In which stage of amelogenesis  does selective matrix withdrawal or resorption occur	In transition stage
In which stage of amelogenesis does cycling of ruffled and smooth bordered ameloblast occur	in maturation stage
In which stage of amelogenesis does the full width of immature enamel matrix is laid down	In transition stage
In which stage of amelogenesis does the rough bordered ameloblast turn smooth	in maturation stage
How long does the maturation stage of enamel lasts	three to four years
The dimension of differentiated ameloblast is	60 micrometer in height and 2-4 micrometers in width
Odontoblast differentiation is mediated by inner enamel epithelium through	transforming growth factor - beta
The pre-ameloblasts releases enzyme by	exocytosis
The non-collagenous protein of odontoblast that mediates epithelium-mesenchymal interaction is	Dentin sialophosphoprotein
In aprismatic enamel near DEJ, the enamel crystallites are arranged	in random orientation
In aprismatic enamel at peripery [outer surface of crown] , the enamel crystallites are arranged	uniformly parallel to each other
The shape of the Tomes process is responsible for	prismatic architechture of enamel
Each enamel prism is formed by	single ameloblast but four contribute to the interprismatic substance
The mineralizing front of enamel is observed under electron microscopy as	honeycomb pattern
Ameloblasts are joined to each other by	terminal bar apparatus distally at the base of the Tome's process
The juntion of terminal web apparatus of ameloblsts is	Zonular in nature
Cell junction at basal end of ameloblasts [near to st.intermedium]	Macular in nature
The prism boundaries of enamel	are formed first giving the deveeloping enamel front a pit-like surface appearance
Initiation of mineralization of enamel is mediated by	Dentin sialophosphoprotein
Ameloblastin determines	the prismatic pattern
Enamel crystallite growth  and nucleation of enamel are controlled by	Tuftlin
Within the enamel prism, the amelogenin are located in the	center of the prism. Non-amelogenins in periphery of the prisms.
Number of rows of ameloblasts that are generated each week at cervical loop is	seven
The transcription factor responsible for regulating cell destiny is	Egr-1
The gene product that is localized to enamel knot is	Msx-2
The regulator of enamel morphogenesis is	Msx-2
The commonest site of enamel pearl formation is	near furcation region in root, nearer to the cervical region