AND CORRECT ANSWERS (PROFESSOR VERIFIED) | LATEST
EDITION
Question 1
Which of the following best describes the primary etiological factor in
plaque-induced gingival diseases?
A) Fungal infections
B) Bacterial biofilm
C) Viral pathogens
D) Allergic reactions
Correct Answer: B) Bacterial biofilm
Rationale: Dental plaque, which is a bacterial biofilm, serves as the
primary etiological factor in plaque-induced gingival diseases. The
bacteria in plaque produce toxins and enzymes that initiate and
perpetuate the inflammatory response in gingival tissues. Without
adequate plaque removal, these bacterial accumulations lead to
gingival inflammation and disease progression.
Question 2
A patient presents with gingival enlargement that is firm, fibrotic, and
painless, affecting primarily the interdental papillae. The patient reports
taking phenytoin for seizure control. What is the most likely diagnosis?
,A) Pregnancy tumor
B) Drug-influenced gingival enlargement
C) Hereditary gingival fibromatosis
D) Leukemic gingival enlargement
Correct Answer: B) Drug-influenced gingival enlargement
Rationale: Phenytoin is a well-known anticonvulsant medication
associated with drug-induced gingival enlargement. The fibrotic,
painless nature of the enlargement and the medication history are
characteristic of this condition. Calcium channel blockers and
cyclosporine are also associated with this type of gingival overgrowth.
The condition typically begins within 1-3 months of starting the
medication.
Question 3
During tooth development, which structure gives rise to the enamel
organ?
A) Dental papilla
B) Dental sac
C) Oral epithelium
D) Neural crest cells
Correct Answer: C) Oral epithelium
Rationale: The enamel organ develops from the oral ectoderm (oral
epithelium) during the bud stage of tooth development. This epithelial
structure is responsible for forming enamel through the differentiation
of ameloblasts. The dental papilla (mesenchymal origin) gives rise to
,dentin and pulp, while the dental sac forms the cementum, periodontal
ligament, and alveolar bone.
Question 4
What is the primary function of the junctional epithelium?
A) To form the outer layer of the gingiva
B) To provide attachment between the gingiva and the tooth surface
C) To produce gingival crevicular fluid
D) To resorb alveolar bone
Correct Answer: B) To provide attachment between the gingiva and the
tooth surface
Rationale: The junctional epithelium is a specialized epithelium that
forms a biological seal around the tooth at the base of the gingival
sulcus. It attaches to the tooth surface via hemidesmosomes and an
internal basal lamina, creating a barrier that protects the underlying
connective tissues from bacterial invasion. This attachment is crucial for
maintaining periodontal health.
Question 5
Which of the following periodontal pathogens is most strongly
associated with aggressive periodontitis?
A) Porphyromonas gingivalis
B) Aggregatibacter actinomycetemcomitans
C) Fusobacterium nucleatum
D) Prevotella intermedia
Correct Answer: B) Aggregatibacter actinomycetemcomitans
, Rationale: Aggregatibacter actinomycetemcomitans (formerly
Actinobacillus actinomycetemcomitans) is the pathogen most strongly
associated with aggressive periodontitis, particularly the localized form.
This organism produces leukotoxin, which destroys polymorphonuclear
leukocytes and monocytes, and has other virulence factors that
contribute to rapid attachment loss and bone destruction, especially in
younger patients.
Question 6
The dental lamina is responsible for forming:
A) Cementum only
B) The permanent dentition only
C) Both primary and permanent dentitions
D) Alveolar bone
Correct Answer: C) Both primary and permanent dentitions
Rationale: The dental lamina is a band of epithelial tissue that
invaginates from the oral epithelium during early tooth development. It
gives rise to the tooth germs for both the primary dentition
(successional lamina) and the permanent dentition (the permanent
successors develop from the lingual extension of the dental lamina).
After tooth formation, the dental lamina typically degenerates.
Question 7
A patient exhibits gingival inflammation limited to the interdental
papillae with no attachment loss. Bleeding on probing is present. What
is the most appropriate diagnosis?