A. Prevent extrusion
B. Prevent rotation
C. Maintains the mesiodistal width
D. All of the above
# The periodontal ligament is approximately :
A. 0.25 mm inn thickness
B. 0.5 mm in thickness
C. 0.75 mm in thickness
D. 1.0 mm in thickness
# Narrowing of periodontl ligament in labially placed mandibular canine with age is due to :
A. Due to deposition of cementum and bone
B. Down growths of gingival epithelium
C. Gingival cysts formed from cell rests
D. Reversal of function of horizontal and oblique fibers
# Centre of the disc of TMJ is :
A. Avascular
B. Devoid of nervous tissue
C. Avascular and devoid of nervous tissue
D. None of the above
# The type of bone present in the labial area of the anterior teeth is:
A. Cortical
B. Cancellous
C. Osteophytic
D. Exophytic
# The component of future TMJ shows development at:
A. 6 weeks
B. 10 weeks
C. 18 weeks
D. 16 weeks
# In a dried skull, holes on the lingual aspects of the deciduous teeth are called:
A. Volkmann canals
B. Canals of Hirschfeld and Zuckerkandl
C. Haversian canals
D. Gubernacular canals
# A special feature of the periodontal ligament fibroblasts is:
A. The number of organelles
B. Presence of actin fibers and shape change
C. Size of the cells
D. Collagen fiber formation