INBDE Oral Biology and Histology 2 — Questions and Answers
Question 1: The epithelial rests of Malassez are remnants of which structure?
- Dental lamina
- Reduced enamel epithelium
- Hertwig's epithelial root sheath (Correct answer)
- Nasmyth's membrane
Correct answer: Hertwig's epithelial root sheath
The epithelial rests of Malassez are remnants of Hertwig's epithelial root sheath that persist in the periodontal ligament throughout life.
Question 2: Which salivary gland produces the most serous secretion?
- Sublingual gland
- Submandibular gland
- Parotid gland (Correct answer)
- Minor labial glands
Correct answer: Parotid gland
The parotid gland is entirely serous and produces a watery, enzyme-rich (amylase) secretion comprising about 25% of total saliva volume.
Question 3: Retzius lines in enamel represent:
- Areas of enamel hypocalcification
- Incremental lines of enamel matrix deposition (Correct answer)
- Directions of enamel rod orientation
- Boundaries between primary and secondary enamel
Correct answer: Incremental lines of enamel matrix deposition
Striae of Retzius are incremental lines in enamel that represent successive layers of enamel matrix deposited during crown formation.
Question 4: Which cells produce the principal fibers of the periodontal ligament?
- Cementoblasts
- Osteoblasts
- Fibroblasts (Correct answer)
- Undifferentiated mesenchymal cells
Correct answer: Fibroblasts
Fibroblasts are the most numerous cells of the periodontal ligament and are responsible for synthesizing and maintaining the collagen fibers.
Question 5: The neonatal line in primary tooth enamel marks the boundary between:
- Prenatal and postnatal enamel (Correct answer)
- Enamel and dentin
- Crown and root enamel
- Outer and inner enamel
Correct answer: Prenatal and postnatal enamel
The neonatal line is a prominent stria of Retzius that marks the junction between prenatally and postnatally formed enamel in primary teeth.
Question 6: Dead tracts in dentin appear black in transmitted light because they contain:
- Bacteria
- Air (Correct answer)
- Blood pigments
- Secondary dentin
Correct answer: Air
Dead tracts are areas where odontoblastic processes have degenerated and the empty dentinal tubules become filled with air, causing them to appear dark in transmitted light.
INBDE Oral Biology and Histology 2
The epithelial rests of Malassez are remnants of which structure?