amelogensis Flashcards
The embryonic cell layer of origin for enamel is _________
Ectodermally derived
Know the proper sequence of events involved in the formation of enamel
Ameloblast formation –> odontoblast formation –> secretion of mantel dentin –> secretion of enamel matrix
The cross striations characteristic of enamel rods represent __________
a. Incremental growth –> Striae of Retzius
b. 24 hours of enamel matrix production, about 4 m/day
Where is gnarled enamel most frequently found?
cusp tips
Amelogenin accounts for approximately ___ % of the protein in enamel matrix
90%
the enamel spindle represent the vestige of a _____ within the mineralized matrix
odontoblastic processes
according to your text, hypomineralization is characterized by what features on the surface of a tooth
opaque coloration (chalky white)
Enamel perikymata are the surface maifestations of the ________
striae of retzius
The presence of a carbonated apatite core renders the hydroxyapatite crystals of enamel
It is now more susceptible to acid dissociation
The Tomes’ process of the ameloblasts is the part of the cell that contains _________
Secretory granules (with alkaline phosphatase)
According to your text, the terminal web region in fully differentiated ameloblasts is
comprised of ___________
Tonofibrils
Hydroxyapatite crystals of enamel are approximately ____ times wider and over ____times greater in length than those of bone, dentin and cementum.
a. 10 times
b. 100 times
Fluoride may substitute for ____ ions, conferring greater stability and resistance to acidic dissolution
Hydroxide (OH)
According to your text, hypoplasia of enamel is characterized by what features?
a. Pits and grooves
b. Notches
A patient presents with a “doubled” central incisor; however, when counting the teeth, the
tooth count reveals a missing tooth when the “double tooth” is counted as one. What is the diagnosis?
fusion
