MCQs on Oral Histology - Enamel Part 3

# The type of fibrous element in enamel is :
A. Tonofilament
B. Keratin like fiber
C. Collagen fiber
D. Vimentin filament

# Calcification in enamel starts at :
A. Enamel Matrix
B. Root

# Specific gravity of enamel is :
A. 2.8
B. 3.8
C. 4.8
D. 2.3

# Inorganic content of enamel is about :
A. 35 %
B. 50 %
C. 4 %
D. 96 %

# Length of enamel rods is :
A. Greater than the thickness of the enamel
B. Less then the thickness of the enamel
C. Equal to the thickness of the enamel
D. None of the above

# The diameter of the rod is:
A. 4 micrometer
B. 9 micrometer
C. 7 micrometer
D. 2 micrometer

# Which of the following statement is correct ?
A. In cross sections enamel rods appear hexagonal and resemble fish scales
B. The bodies of rods are near occlusal and incisal surfaces , whereas the tails point cervically
C. The apatite crystals are parallel to bodies and deviate 65 degrees from the tails
D. All of the above

# Which of the following is true about direction of enamel rods?
A. They originate at right angle to dentin surface
B. They are almost vertical near the incisal edge or cusp tip areas
C. In the cervical third of deciduous crowns they are almost horizontal in direction
D. In cervical region of permanent teeth , they deviate in apical direction
E. All of the above

# Thin leaf like structures that extend from enamel surface into the DEJ are :
A. Enamel spindles
B. Enamel lamella
C. Enamel Tufts
D. Perikymata

# Dentinoenamel junction is :
A. Non scalloped
B. Straight
C. Scalloped and the convexities are directed towards dentin
D. Scalloped and the convexities are directed towards enamel